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MATLAB – Strings ”; Previous Next Creating a character string is quite simple in MATLAB. In fact, we have used it many times. For example, you type the following in the command prompt − Live Demo my_string = ”Tutorials Point” MATLAB will execute the above statement and return the following result − my_string = Tutorials Point MATLAB considers all variables as arrays, and strings are considered as character arrays. Let us use the whos command to check the variable created above − whos MATLAB will execute the above statement and return the following result − Name Size Bytes Class Attributes my_string 1×16 32 char Interestingly, you can use numeric conversion functions like uint8 or uint16 to convert the characters in the string to their numeric codes. The char function converts the integer vector back to characters − Example Create a script file and type the following code into it − Live Demo my_string = ”Tutorial””s Point”; str_ascii = uint8(my_string) % 8-bit ascii values str_back_to_char= char(str_ascii) str_16bit = uint16(my_string) % 16-bit ascii values str_back_to_char = char(str_16bit) When you run the file, it displays the following result − str_ascii = 84 117 116 111 114 105 97 108 39 115 32 80 111 105 110 116 str_back_to_char = Tutorial”s Point str_16bit = 84 117 116 111 114 105 97 108 39 115 32 80 111 105 110 116 str_back_to_char = Tutorial”s Point Rectangular Character Array The strings we have discussed so far are one-dimensional character arrays; however, we need to store more than that. We need to store more dimensional textual data in our program. This is achieved by creating rectangular character arrays. Simplest way of creating a rectangular character array is by concatenating two or more one-dimensional character arrays, either vertically or horizontally as required. You can combine strings vertically in either of the following ways − Using the MATLAB concatenation operator [] and separating each row with a semicolon (;). Please note that in this method each row must contain the same number of characters. For strings with different lengths, you should pad with space characters as needed. Using the char function. If the strings are of different lengths, char pads the shorter strings with trailing blanks so that each row has the same number of characters. Example Create a script file and type the following code into it − Live Demo doc_profile = [”Zara Ali ”; … ”Sr. Surgeon ”; … ”R N Tagore Cardiology Research Center”] doc_profile = char(”Zara Ali”, ”Sr. Surgeon”, … ”RN Tagore Cardiology Research Center”) When you run the file, it displays the following result − doc_profile = Zara Ali Sr. Surgeon R N Tagore Cardiology Research Center doc_profile = Zara Ali Sr. Surgeon RN Tagore Cardiology Research Center You can combine strings horizontally in either of the following ways − Using the MATLAB concatenation operator, [] and separating the input strings with a comma or a space. This method preserves any trailing spaces in the input arrays. Using the string concatenation function, strcat. This method removes trailing spaces in the inputs. Example Create a script file and type the following code into it − Live Demo name = ”Zara Ali ”; position = ”Sr. Surgeon ”; worksAt = ”R N Tagore Cardiology Research Center”; profile = [name ”, ” position ”, ” worksAt] profile = strcat(name, ”, ”, position, ”, ”, worksAt) When you run the file, it displays the following result − profile = Zara Ali , Sr. Surgeon , R N Tagore Cardiology Research Center profile = Zara Ali,Sr. Surgeon,R N Tagore Cardiology Research Center Combining Strings into a Cell Array From our previous discussion, it is clear that combining strings with different lengths could be a pain as all strings in the array has to be of the same length. We have used blank spaces at the end of strings to equalize their length. However, a more efficient way to combine the strings is to convert the resulting array into a cell array. MATLAB cell array can hold different sizes and types of data in an array. Cell arrays provide a more flexible way to store strings of varying length. The cellstr function converts a character array into a cell array of strings. Example Create a script file and type the following code into it − Live Demo name = ”Zara Ali ”; position = ”Sr. Surgeon ”; worksAt = ”R N Tagore Cardiology Research Center”; profile = char(name, position, worksAt); profile = cellstr(profile); disp(profile) When you run the file, it displays the following result − { [1,1] = Zara Ali [2,1] = Sr. Surgeon [3,1] = R N Tagore Cardiology Research Center } String Functions in MATLAB MATLAB provides numerous string functions creating, combining, parsing, comparing and manipulating strings. Following table provides brief description of the string functions in MATLAB − Function Purpose Functions for storing text in character arrays, combine character arrays, etc. blanks Create string of blank characters cellstr Create cell array of strings from character array char Convert to character array (string) iscellstr Determine whether input is cell array of strings ischar Determine whether item is character array sprintf Format data into string strcat Concatenate strings horizontally strjoin Join strings in cell array into single string Functions for identifying parts of strings, find and replace substrings ischar Determine whether item is character array isletter Array elements that are alphabetic letters isspace Array elements that are space characters isstrprop Determine whether string is of specified category sscanf Read formatted data from string strfind Find one string within another strrep Find and replace substring strsplit Split string at specified delimiter strtok Selected parts of string validatestring Check validity of text string symvar Determine symbolic variables in expression regexp Match regular expression (case sensitive) regexpi Match regular expression (case insensitive) regexprep Replace string using regular expression regexptranslate Translate string into regular expression Functions for string comparison strcmp Compare strings (case sensitive) strcmpi Compare strings (case insensitive) strncmp Compare first n characters of strings (case sensitive) strncmpi