Category: Computer Programming

Computer Programming – Characters ”; Previous Next If it was easy to work with numbers in computer programming, it would be even easier to work with characters. Characters are simple alphabets like a, b, c, d…., A, B, C, D,….., but with an exception. In computer programming, any single digit number like 0, 1, 2,….and special characters like $, %, +, -…. etc., are also treated as characters and to assign them in a character type variable, you simply need to put them inside single quotes. For example, the following statement defines a character type variable ch and we assign a value ”a” to it − char ch = ”a”; Here, ch is a variable of character type which can hold a character of the implementation”s character set and ”a” is called a character literal or a character constant. Not only a, b, c,…. but when any number like 1, 2, 3…. or any special character like !, @, #, #, $,…. is kept inside single quotes, then they will be treated as a character literal and can be assigned to a variable of character type, so the following is a valid statement − char ch = ”1”; A character data type consumes 8 bits of memory which means you can store anything in a character whose ASCII value lies in between -127 to 127, so it can hold any of the 256 different values. A character data type can store any of the characters available on your keyboard including special characters like !, @, #, #, $, %, ^, &, *, (, ), _, +, {, }, etc. Note that you can keep only a single alphabet or a single digit number inside single quotes and more than one alphabets or digits are not allowed inside single quotes. So the following statements are invalid in C programming − char ch1 = ”ab”; char ch2 = ”10”; Given below is a simple example, which shows how to define, assign, and print characters in C Programming language − Live Demo #include <stdio.h> int main() { char ch1; char ch2; char ch3; char ch4; ch1 = ”a”; ch2 = ”1”; ch3 = ”$”; ch4 = ”+”; printf( “ch1: %cn”, ch1); printf( “ch2: %cn”, ch2); printf( “ch3: %cn”, ch3); printf( “ch4: %cn”, ch4); } Here, we used %c to print a character data type. When the above program is executed, it produces the following result − ch1: a ch2: 1 ch3: $ ch4: + Escape Sequences Many programming languages support a concept called Escape Sequence. When a character is preceded by a backslash (), it is called an escape sequence and it has a special meaning to the compiler. For example, n in the following statement is a valid character and it is called a new line character − char ch = ”n”; Here, character n has been preceded by a backslash (), it has special meaning which is a new line but keep in mind that backslash () has special meaning with a few characters only. The following statement will not convey any meaning in C programming and it will be assumed as an invalid statement − char ch = ”1”; The following table lists the escape sequences available in C programming language − Escape Sequence Description t Inserts a tab in the text at this point. b Inserts a backspace in the text at this point. n Inserts a newline in the text at this point. r Inserts a carriage return in the text at this point. f Inserts a form feed in the text at this point. ” Inserts a single quote character in the text at this point. “ Inserts a double quote character in the text at this point. \ Inserts a backslash character in the text at this point. The following example shows how the compiler interprets an escape sequence in a print statement − Live Demo #include <stdio.h> int main() { char ch1; char ch2; char ch3; char ch4; ch1 = ”t”; ch2 = ”n”; printf( “Test for tabspace %c and a newline %c will start here”, ch1, ch2); } When the above program is executed, it produces the following result − Test for tabspace and a newline will start here Characters in Java Following is the equivalent program written in Java. Java handles character data types much in the same way as we have seen in C programming. However, Java provides additional support for character manipulation. You can try to execute the following program to see the output, which must be identical to the result generated by the above C example. Live Demo public class DemoJava { public static void main(String []args) { char ch1; char ch2; char ch3; char ch4; ch1 = ”a”; ch2 = ”1”; ch3 = ”$”; ch4 = ”+”; System.out.format( “ch1: %cn”, ch1); System.out.format( “ch2: %cn”, ch2); System.out.format( “ch3: %cn”, ch3); System.out.format( “ch4: %cn”, ch4); } } When the above program is executed, it produces the following result − ch1: a ch2: 1 ch3: $ ch4: + Java also supports escape sequence in the same way you have used them in C programming. Characters in Python Python does not support any character data type but all the characters are treated as string, which is a sequence of characters. We will study strings in a separate chapter. You do not need to have any special arrangement while using a single character in Python. Following is the equivalent program written in Python − Live Demo ch1 = ”a”; ch2 = ”1”; ch3 = ”$”; ch4 = ”+”; print “ch1: “, ch1 print “ch2: “, ch2 print “ch3: “, ch3 print “ch4: “, ch4 When the above program is executed, it produces the following result − ch1: a ch2: 1 ch3: $ ch4: + Python supports escape sequences in the same way as you have used them in C programming. Print Page Previous Next

Computer Programming – Operators ”; Previous Next An operator in a programming language is a symbol that tells the compiler or interpreter to perform specific mathematical, relational or logical operation and produce final result. This chapter will explain the concept of operators and it will take you through the important arithmetic and relational operators available in C, Java, and Python. Arithmetic Operators Computer programs are widely used for mathematical calculations. We can write a computer program which can do simple calculation like adding two numbers (2 + 3) and we can also write a program, which can solve a complex equation like P(x) = x4 + 7×3 – 5x + 9. If you have been even a poor student, you must be aware that in first expression 2 and 3 are operands and + is an operator. Similar concepts exist in Computer Programming. Take a look at the following two examples − 2 + 3 P(x) = x4 + 7×3 – 5x + 9. These two statements are called arithmetic expressions in a programming language and plus, minus used in these expressions are called arithmetic operators and the values used in these expressions like 2, 3 and x, etc., are called operands. In their simplest form, such expressions produce numerical results. Similarly, a programming language provides various arithmetic operators. The following table lists down a few of the important arithmetic operators available in C programming language. Assume variable A holds 10 and variable B holds 20, then − Operator Description Example + Adds two operands A + B will give 30 – Subtracts second operand from the first A – B will give -10 * Multiplies both operands A * B will give 200 / Divides numerator by de-numerator B / A will give 2 % This gives remainder of an integer division B % A will give 0 Following is a simple example of C Programming to understand the above mathematical operators − Live Demo #include <stdio.h> int main() { int a, b, c; a = 10; b = 20; c = a + b; printf( “Value of c = %dn”, c); c = a – b; printf( “Value of c = %dn”, c); c = a * b; printf( “Value of c = %dn”, c); c = b / a; printf( “Value of c = %dn”, c); c = b % a; printf( “Value of c = %dn”, c); } When the above program is executed, it produces the following result − Value of c = 30 Value of c = -10 Value of c = 200 Value of c = 2 Value of c = 0 Relational Operators Consider a situation where we create two variables and assign them some values as follows − A = 20 B = 10 Here, it is obvious that variable A is greater than B in values. So, we need the help of some symbols to write such expressions which are called relational expressions. If we use C programming language, then it will be written as follows − (A > B) Here, we used a symbol > and it is called a relational operator and in their simplest form, they produce Boolean results which means the result will be either true or false. Similarly, a programming language provides various relational operators. The following table lists down a few of the important relational operators available in C programming language. Assume variable A holds 10 and variable B holds 20, then − Operator Description Example == Checks if the values of two operands are equal or not, if yes then condition becomes true. (A == B) is not true. != Checks if the values of two operands are equal or not, if values are not equal then condition becomes true. (A != B) is true. > Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true. (A > B) is not true. < Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true. (A < B) is true. >= Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true. (A >= B) is not true. <= Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true. (A <= B) is true. Here, we will show you one example of C Programming which makes use of if conditional statement. Though this statement will be discussed later in a separate chapter, but in short, we use if statement to check a condition and if the condition is true, then the body of if statement is executed, otherwise the body of if statement is skipped. Live Demo #include <stdio.h> int main() { int a, b; a = 10; b = 20; /* Here we check whether a is equal to 10 or not */ if( a == 10 ) { /* if a is equal to 10 then this body will be executed */ printf( “a is equal to 10n”); } /* Here we check whether b is equal to 10 or not */ if( b == 10 ) { /* if b is equal to 10 then this body will be executed */ printf( “b is equal to 10n”); } /* Here we check if a is less b than or not */ if( a < b ) { /* if a is less than b then this body will be executed */ printf( “a is less than bn”); } /* Here we check whether a and b are not equal */ if( a != b ) { /* if a is not equal to b then this body will be executed */ printf( “a is not equal to bn”); } } When the above program is executed, it produces the

Computer Programming – Data Types ”; Previous Next Let”s discuss about a very simple but very important concept available in almost all the programming languages which is called data types. As its name indicates, a data type represents a type of the data which you can process using your computer program. It can be numeric, alphanumeric, decimal, etc. Let’s keep Computer Programming aside for a while and take an easy example of adding two whole numbers 10 & 20, which can be done simply as follows − 10 + 20 Let”s take another problem where we want to add two decimal numbers 10.50 & 20.50, which will be written as follows − 10.50 + 20.50 The two examples are straightforward. Now let”s take another example where we want to record student information in a notebook. Here we would like to record the following information − Name: Class: Section: Age: Sex: Now, let”s put one student record as per the given requirement − Name: Zara Ali Class: 6th Section: J Age: 13 Sex: F The first example dealt with whole numbers, the second example added two decimal numbers, whereas the third example is dealing with a mix of different data. Let”s put it as follows − Student name “Zara Ali” is a sequence of characters which is also called a string. Student class “6th” has been represented by a mix of whole number and a string of two characters. Such a mix is called alphanumeric. Student section has been represented by a single character which is ”J”. Student age has been represented by a whole number which is 13. Student sex has been represented by a single character which is ”F”. This way, we realized that in our day-to-day life, we deal with different types of data such as strings, characters, whole numbers (integers), and decimal numbers (floating point numbers). Similarly, when we write a computer program to process different types of data, we need to specify its type clearly; otherwise the computer does not understand how different operations can be performed on that given data. Different programming languages use different keywords to specify different data types. For example, C and Java programming languages use int to specify integer data, whereas char specifies a character data type. Subsequent chapters will show you how to use different data types in different situations. For now, let”s check the important data types available in C, Java, and Python and the keywords we will use to specify those data types. C and Java Data Types C and Java support almost the same set of data types, though Java supports additional data types. For now, we are taking a few common data types supported by both the programming languages − Type Keyword Value range which can be represented by this data type Character char -128 to 127 or 0 to 255 Number int -32,768 to 32,767 or -2,147,483,648 to 2,147,483,647 Small Number short -32,768 to 32,767 Long Number long -2,147,483,648 to 2,147,483,647 Decimal Number float 1.2E-38 to 3.4E+38 till 6 decimal places These data types are called primitive data types and you can use these data types to build more complex data types, which are called user-defined data type, for example a string will be a sequence of characters. Python Data Types Python has five standard data types but this programming language does not make use of any keyword to specify a particular data type, rather Python is intelligent enough to understand a given data type automatically. Numbers String List Tuple Dictionary Here, Number specifies all types of numbers including decimal numbers and string represents a sequence of characters with a length of 1 or more characters. For now, let”s proceed with these two data types and skip List, Tuple, and Dictionary, which are advanced data types in Python. Print Page Previous Next Advertisements ”;

Computer Programming – Variables ”; Previous Next Variables are the names you give to computer memory locations which are used to store values in a computer program. For example, assume you want to store two values 10 and 20 in your program and at a later stage, you want to use these two values. Let”s see how you will do it. Here are the following three simple steps − Create variables with appropriate names. Store your values in those two variables. Retrieve and use the stored values from the variables. Creating variables Creating variables is also called declaring variables in C programming. Different programming languages have different ways of creating variables inside a program. For example, C programming has the following simple way of creating variables − #include <stdio.h> int main() { int a; int b; } The above program creates two variables to reserve two memory locations with names a and b. We created these variables using int keyword to specify variable data type which means we want to store integer values in these two variables. Similarly, you can create variables to store long, float, char or any other data type. For example − /* variable to store long value */ long a; /* variable to store float value */ float b; You can create variables of similar type by putting them in a single line but separated by comma as follows − #include <stdio.h> int main() { int a, b; } Listed below are the key points about variables that you need to keep in mind − A variable name can hold a single type of value. For example, if variable a has been defined int type, then it can store only integer. C programming language requires a variable creation, i.e., declaration before its usage in your program. You cannot use a variable name in your program without creating it, though programming language like Python allows you to use a variable name without creating it. You can use a variable name only once inside your program. For example, if a variable a has been defined to store an integer value, then you cannot define a again to store any other type of value. There are programming languages like Python, PHP, Perl, etc., which do not want you to specify data type at the time of creating variables. So you can store integer, float, or long without specifying their data type. You can give any name to a variable like age, sex, salary, year1990 or anything else you like to give, but most of the programming languages allow to use only limited characters in their variables names. For now, we will suggest to use only a….z, A….Z, 0….9 in your variable names and start their names using alphabets only instead of digits. Almost none of the programming languages allow to start their variable names with a digit, so 1990year will not be a valid variable name whereas year1990 or ye1990ar are valid variable names. Every programming language provides more rules related to variables and you will learn them when you will go in further detail of that programming language. Store Values in Variables You have seen how we created variables in the previous section. Now, let”s store some values in those variables − #include <stdio.h> int main() { int a; int b; a = 10; b = 20; } The above program has two additional statements where we are storing 10 in variable a and 20 is being stored in variable b. Almost all the programming languages have similar way of storing values in variable where we keep variable name in the left hand side of an equal sign = and whatever value we want to store in the variable, we keep that value in the right hand side. Now, we have completed two steps, first we created two variables and then we stored required values in those variables. Now variable a has value 10 and variable b has value 20. In other words we can say, when above program is executed, the memory location named a will hold 10 and memory location b will hold 20. Access stored values in variables If we do not use the stored values in the variables, then there is no point in creating variables and storing values in them. We know that the above program has two variables a and b and they store the values 10 and 20, respectively. So let”s try to print the values stored in these two variables. Following is a C program, which prints the values stored in its variables − Live Demo #include <stdio.h> int main() { int a; int b; a = 10; b = 20; printf( “Value of a = %dn”, a ); printf( “Value of b = %dn”, b ); } When the above program is executed, it produces the following result − Value of a = 10 Value of b = 20 You must have seen printf() function in the previous chapter where we had used it to print “Hello, World!”. This time, we are using it to print the values of variables. We are making use of %d, which will be replaced with the values of the given variable in printf() statements. We can print both the values using a single printf() statement as follows − Live Demo #include <stdio.h> int main() { int a; int b; a = 10; b = 20; printf( “Value of a = %d and value of b = %dn”, a, b ); } When the above program is executed, it produces the following result − Value of a = 10 and value of b = 20 If you want to use float variable in C programming, then you will have to use %f instead of %d, and if you want to print a character value, then you will have to use %c. Similarly, different data types can be printed using different % and characters. Variables in Java Following is the equivalent

Computer Programming – File I/O ”; Previous Next Computer Files A computer file is used to store data in digital format like plain text, image data, or any other content. Computer files can be organized inside different directories. Files are used to keep digital data, whereas directories are used to keep files. Computer files can be considered as the digital counterpart of paper documents. While programming, you keep your source code in text files with different extensions, for example, C programming files end with the extension .c, Java programming files with .java, and Python files with .py. File Input/Output Usually, you create files using text editors such as notepad, MS Word, MS Excel or MS Powerpoint, etc. However, many times, we need to create files using computer programs as well. We can modify an existing file using a computer program. File input means data that is written into a file and file output means data that is read from a file. Actually, input and output terms are more related to screen input and output. When we display a result on the screen, it is called output. Similarly, if we provide some input to our program from the command prompt, then it is called input. For now, it is enough to remember that writing into a file is file input and reading something from a file is file output. File Operation Modes Before we start working with any file using a computer program, either we need to create a new file if it does not exist or open an already existing file. In either case, we can open a file in the following modes − Read-Only Mode − If you are going to just read an existing file and you do not want to write any further content in the file, then you will open the file in read-only mode. Almost all the programming languages provide syntax to open files in read-only mode. Write-Only Mode − If you are going to write into either an existing file or a newly created file but you do not want to read any written content from that file, then you will open the file in write-only mode. All the programming languages provide syntax to open files in write-only mode. Read & Write Mode − If you are going to read as well as write into the same file, then you will open file in read & write mode. Append Mode − When you open a file for writing, it allows you to start writing from the beginning of the file; however it will overwrite existing content, if any. Suppose we don’t want to overwrite any existing content, then we open the file in append mode. Append mode is ultimately a write mode, which allows content to be appended at the end of the file. Almost all the programming languages provide syntax to open files in append mode. In the following sections, we will learn how to open a fresh new file, how to write into it, and later, how to read and append more content into the same file. Opening Files You can use the fopen() function to create a new file or to open an existing file. This call will initialize an object of the type FILE, which contains all the information necessary to control the stream. Here is the prototype, i.e., signature of this function call − FILE *fopen( const char * filename, const char * mode ); Here, filename is string literal, which you will use to name your file and access mode can have one of the following values − Sr.No Mode & Description 1 r Opens an existing text file for reading purpose. 2 w Opens a text file for writing. If it does not exist, then a new file is created. Here, your program will start writing content from the beginning of the file. 3 a Opens a text file for writing in appending mode. If it does not exist, then a new file is created. Here, your program will start appending content in the existing file content. 4 r+ Opens a text file for reading and writing both. 5 w+ Opens a text file for both reading and writing. It first truncates the file to zero length, if it exists; otherwise creates the file if it does not exist. 6 a+ Opens a text file for both reading and writing. It creates a file, if it does not exist. The reading will start from the beginning, but writing can only be appended. Closing a File To close a file, use the fclose( ) function. The prototype of this function is − int fclose( FILE *fp ); The fclose( ) function returns zero on success, or EOF, special character, if there is an error in closing the file. This function actually flushes any data still pending in the buffer to the file, closes the file, and releases any memory used for the file. The EOF is a constant defined in the header file stdio.h. There are various functions provided by C standard library to read and write a file character by character or in the form of a fixed length string. Let us see a few of them in the next section. Writing a File Given below is the simplest function to write individual characters to a stream − int fputc( int c, FILE *fp ); The function fputc() writes the character value of the argument c to the output stream referenced by fp. It returns the written character written on success, otherwise EOF if there is an error. You can use the following functions to write a null-terminated string to a stream − int fputs( const char *s, FILE *fp ); The function fputs() writes the string s into the file referenced by fp. It returns a non-negative value on success, otherwise EOF is returned in case of any error. You can also use the function int fprintf(FILE *fp,const char *format, …) to

Computer Programming – Basic Syntax ”; Previous Next Let’s start with a little coding, which will really make you a computer programmer. We are going to write a single-line computer program to write Hello, World! on your screen. Let’s see how it can be written using different programming languages. Hello World Program in C Try the following example using our online compiler option available at www.compileonline.com. For most of the examples given in this tutorial, you will find a Try it option in our website code sections at the top right corner that will take you to the online compiler. Try to change the content inside printf(), i.e., type anything in place of Hello World! and then check its result. It just prints whatever you keep inside the two double quotes. Live Demo #include <stdio.h> int main() { /* printf() function to write Hello, World! */ printf( “Hello, World!” ); } which produces the following result − Hello, World! This little Hello World program will help us understand various basic concepts related to C Programming. Program Entry Point For now, just forget about the #include <stdio.h> statement, but keep a note that you have to put this statement at the top of a C program. Every C program starts with main(), which is called the main function, and then it is followed by a left curly brace. The rest of the program instruction is written in between and finally a right curly brace ends the program. The coding part inside these two curly braces is called the program body. The left curly brace can be in the same line as main(){ or in the next line like it has been mentioned in the above program. Functions Functions are small units of programs and they are used to carry out a specific task. For example, the above program makes use of two functions: main() and printf(). Here, the function main() provides the entry point for the program execution and the other function printf() is being used to print an information on the computer screen. You can write your own functions which we will see in a separate chapter, but C programming itself provides various built-in functions like main(), printf(), etc., which we can use in our programs based on our requirement. Some of the programming languages use the word sub-routine instead of function, but their functionality is more or less the same. Comments A C program can have statements enclosed inside /*…..*/. Such statements are called comments and these comments are used to make the programs user friendly and easy to understand. The good thing about comments is that they are completely ignored by compilers and interpreters. So you can use whatever language you want to write your comments. Whitespaces When we write a program using any programming language, we use various printable characters to prepare programming statements. These printable characters are a, b, c,……z, A, B, C,…..Z, 1, 2, 3,…… 0, !, @, #, $, %, ^, &, *, (, ), -, _, +, =, , |, {, }, [, ], :, ;, <, >, ?, /, , ~. `. “, ”. Hope I”m not missing any printable characters from your keyboard. Apart from these characters, there are some characters which we use very frequently but they are invisible in your program and these characters are spaces, tabs (t), new lines(n). These characters are called whitespaces. These three important whitespace characters are common in all the programming languages and they remain invisible in your text document − Whitespace Explanation Representation New Line To create a new line n Tab To create a tab. t Space To create a space. empty space A line containing only whitespace, possibly with a comment, is known as a blank line, and a C compiler totally ignores it. Whitespace is the term used in C to describe blanks, tabs, newline characters, and comments. So you can write printf(“Hello, World!” ); as shown below. Here all the created spaces around “Hello, World!” are useless and the compiler will ignore them at the time of compilation. Live Demo #include <stdio.h> int main() { /* printf() function to write Hello, World! */ printf( “Hello, World!” ); } which produces the following result − Hello, World! If we make all these whitespace characters visible, then the above program will look like this and you will not be able to compile it − #include <stdio.h>n n int main()n { n t/* printf() function to write Hello, World! */ n tprintf(t”Hello, World!”t);n n }n Semicolons Every individual statement in a C Program must be ended with a semicolon (;), for example, if you want to write “Hello, World!” twice, then it will be written as follows − Live Demo #include <stdio.h> int main() { /* printf() function to write Hello, World! */ printf( “Hello, World!n” ); printf( “Hello, World!” ); } This program will produce the following result − Hello, World! Hello, World! Here, we are using a new line character n in the first printf() function to create a new line. Let us see what happens if we do not use this new line character − Live Demo #include <stdio.h> int main() { /* printf() function to write Hello, World! */ printf( “Hello, World!” ); printf( “Hello, World!” ); } This program will produce the following result − Hello, World! Hello, World! We will learn identifiers and keywords in next few chapters. Program Explanation Let us understand how the above C program works. First of all, the above program is converted into a binary format using C compiler. So let’s put this code in test.c file and compile it as follows − $gcc test.c -o demo If there is any grammatical error (Syntax errors in computer terminologies), then we fix it before converting it into binary format. If everything goes fine, then it produces a binary file called demo. Finally, we execute the produced binary demo as follows − $./demo which produces the following result −

Computer Programming – Keywords ”; Previous Next So far, we have covered two important concepts called variables and their data types. We discussed how to use int, long, and float to specify different data types. We also learnt how to name the variables to store different values. Though this chapter is not required separately because reserved keywords are a part of basic programming syntax, we kept it separate to explain it right after data types and variables to make it easy to understand. Like int, long, and float, there are many other keywords supported by C programming language which we will use for different purpose. Different programming languages provide different set of reserved keywords, but there is one important & common rule in all the programming languages that we cannot use a reserved keyword to name our variables, which means we cannot name our variable like int or float rather these keywords can only be used to specify a variable data type. For example, if you will try to use any reserved keyword for the purpose of variable name, then you will get a syntax error. Live Demo #include <stdio.h> int main() { int float; float = 10; printf( “Value of float = %dn”, float); } When you compile the above program, it produces the following error − main.c: In function ”main”: main.c:5:8: error: two or more data types in declaration specifiers int float; …… Let”s now give a proper name to our integer variable, then the above program should compile and execute successfully − Live Demo #include <stdio.h> int main() { int count; count = 10; printf( “Value of count = %dn”, count); } C Programming Reserved Keywords Here is a table having almost all the keywords supported by C Programming language − auto else long switch break enum register typedef case extern return union char float short unsigned const for signed void continue goto sizeof volatile default if static while do int struct _Packed double Java Programming Reserved Keywords Here is a table having almost all the keywords supported by Java Programming language − abstract assert boolean break byte case catch char class const continue default do double else enum extends final finally float for goto if implements import instanceof int interface long native new package private protected public return short static strictfp super switch synchronized this throw throws transient try void volatile while Python Programming Reserved Keywords Here is a table having almost all the keywords supported by Python Programming language − and exec not assert finally or break for pass class from print continue global raise def if return del import try elif in while else is with except lambda yield We know you cannot memorize all these keywords, but we have listed them down for your reference purpose and to explain the concept of reserved keywords. So just be careful while giving a name to your variable, you should not use any reserved keyword for that programming language. Print Page Previous Next Advertisements ”;

Computer Programming Tutorial PDF Version Quick Guide Resources Job Search Discussion Computer programming is the act of writing computer programs, which are a sequence of instructions written using a Computer Programming Language to perform a specified task by the computer. Computer Programming is fun and easy to learn provided you adopt a proper approach. This tutorial attempts to cover the basics of computer programming using a simple and practical approach for the benefit of novice learners. Audience This tutorial has been prepared for the beginners who are willing to learn computer programming but they are unable to learn it due to lack of proper guidance. We are confident that after completing this tutorial, you will be at a level where you can code in C Programming language and will have a basic understanding of Java and Python programming languages as well from where you can continue further. If you are completely new to Computer Programming, then we recommend you to read this tutorial twice or even thrice. First reading will not give you much idea, but during your second reading, you will start grasping most of the concepts and you will enjoy writing computer programs. Prerequisites We do not expect much from you as prerequisites, however, we assume that you have some amount of exposure to computers and its peripherals like keyboard, mouse, screen, printer, etc. Print Page Previous Next Advertisements ”;

Computer Programming – Basics ”; Previous Next We assume you are well aware of English Language, which is a well-known Human Interface Language. English has a predefined grammar, which needs to be followed to write English statements in a correct way. Likewise, most of the Human Interface Languages (Hindi, English, Spanish, French, etc.) are made of several elements like verbs, nouns, adjectives, adverbs, propositions, and conjunctions, etc. Similar to Human Interface Languages, Computer Programming Languages are also made of several elements. We will take you through the basics of those elements and make you comfortable to use them in various programming languages. These basic elements include − Programming Environment Basic Syntax Data Types Variables Keywords Basic Operators Decision Making Loops Numbers Characters Arrays Strings Functions File I/O We will explain all these elements in subsequent chapters with examples using different programming languages. First, we will try to understand the meaning of all these terms in general and then, we will see how these terms can be used in different programming languages. This tutorial has been designed to give you an idea about the following most popular programming languages − C Programming Java Programming Python Programming A major part of the tutorial has been explained by taking C as programming language and then we have shown how similar concepts work in Java and Python. So after completion of this tutorial, you will be quite familiar with these popular programming languages. Print Page Previous Next Advertisements ”;

Computer Programming – Environment ”; Previous Next Though Environment Setup is not an element of any Programming Language, it is the first step to be followed before setting on to write a program. When we say Environment Setup, it simply implies a base on top of which we can do our programming. Thus, we need to have the required software setup, i.e., installation on our PC which will be used to write computer programs, compile, and execute them. For example, if you need to browse Internet, then you need the following setup on your machine − A working Internet connection to connect to the Internet A Web browser such as Internet Explorer, Chrome, Safari, etc. If you are a PC user, then you will recognize the following screenshot, which we have taken from the Internet Explorer while browsing tutorialspoint.com. Similarly, you will need the following setup to start with programming using any programming language. A text editor to create computer programs. A compiler to compile the programs into binary format. An interpreter to execute the programs directly. In case you don’t have sufficient exposure to computers, you will not be able to set up either of these software. So, we suggest you take the help from any technical person around you to set up the programming environment on your machine from where you can start. But for you, it is important to understand what these items are. Text Editor A text editor is a software that is used to write computer programs. Your Windows machine must have a Notepad, which can be used to type programs. You can launch it by following these steps − Start Icon → All Programs → Accessories → Notepad → Mouse Click on Notepad It will launch Notepad with the following window − You can use this software to type your computer program and save it in a file at any location. You can download and install other good editors like Notepad++, which is freely available. If you are a Mac user, then you will have TextEdit or you can install some other commercial editor like BBEdit to start with. Compiler? You write your computer program using your favorite programming language and save it in a text file called the program file. Now let us try to get a little more detail on how the computer understands a program written by you using a programming language. Actually, the computer cannot understand your program directly given in the text format, so we need to convert this program in a binary format, which can be understood by the computer. The conversion from text program to binary file is done by another software called Compiler and this process of conversion from text formatted program to binary format file is called program compilation. Finally, you can execute binary file to perform the programmed task. We are not going into the details of a compiler and the different phases of compilation. The following flow diagram gives an illustration of the process − So, if you are going to write your program in any such language, which needs compilation like C, C++, Java and Pascal, etc., then you will need to install their compilers before you start programming. Interpreter We just discussed about compilers and the compilation process. Compilers are required in case you are going to write your program in a programming language that needs to be compiled into binary format before its execution. There are other programming languages such as Python, PHP, and Perl, which do not need any compilation into binary format, rather an interpreter can be used to read such programs line by line and execute them directly without any further conversion. So, if you are going to write your programs in PHP, Python, Perl, Ruby, etc., then you will need to install their interpreters before you start programming. Online Compilation If you are not able to set up any editor, compiler, or interpreter on your machine, then tutorialspoint.com provides a facility to compile and run almost all the programs online with an ease of a single click. So do not worry and let”s proceed further to have a thrilling experience to become a computer programmer in simple and easy steps. Print Page Previous Next Advertisements ”;