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An operator defines some function that will be performed on the data. The values on which the operators work are called operands. Consider the following expression
7 + 5 = 12
Here, the values 7, 5, and 12 are operands, while + and = are operators.
The major operators in Elm can be classified as −
- Arithmetic
- Relational
- Logical
Arithmetic Operators
Assume the values in variables a and b are 7 and 2 respectively.
| Sr. No. | Operator | Description | Example |
|---|---|---|---|
| 1 | +(Addition) | returns the sum of the operands | a+b is 9 |
| 2 | -(Subtraction) | returns the difference of the values | a-b is 5 |
| 3 | * (Multiplication) | returns the product of the values | a*b is 14 |
| 4 | / (Float Division) | performs division operation and returns a float quotient | a / b is 3.5 |
| 5 | //(Integer Division) | performs division operation and returns a integer quotient | a // b is 3 |
| 6 | % (Modulus) | performs division operation and returns the remainder | a % b is 1 |
Relational Operators
Relational Operators test or define the kind of relationship between two entities. These operators are used to compare two or more values. Relational operators return a Boolean value, i.e. true or false.
Assume the value of a is 10 and b is 20.
| Sr. No. | Operator | Description | Example |
|---|---|---|---|
| 1 | > | Greater than | (a > b) is False |
| 2 | < | Lesser than | (a < b) is True |
| 3 | >= | Greater than or equal to | (a >= b) is False |
| 4 | <= | Lesser than or equal to | (a <= b) is True |
| 5 | == | Equality | (a == b) is false |
| 6 | != | Not equal | (a != b) is True |
Comparable Types
Comparison operators like >= or < work with comparable types. These are defined as numbers, characters, strings, and lists, tuples. The comparable types on both sides of the operator must be the same.
| Sr. No. | Comparable Type | Example |
|---|---|---|
| 1 | number | 7>2 gives True |
| 2 | character | ”a” ==”b” gives False |
| 3 | string | “hello” ==”hello” gives True |
| 4 | tuple | (1,”One”)==(1,”One”) gives True |
| 5 | list | [1,2]==[1,2] gives True |
Open the elm REPL and try the examples shown below −
C:Usersadmin>elm repl ---- elm-repl 0.18.0 ----------------------------------------------------------- :help for help, :exit to exit, more at <https://github.com/elm-lang/elm-repl> -------------------------------------------------------------------------------- > 7>2 True : Bool > 7.0>2 True : Bool > 7.0<2.0 False : Bool > ''a'' > ''b'' False : Bool > ''a'' < ''b'' True : Bool > "a" < "b" True : Bool > (1,2) > (2,3) False : Bool > [''1'',''3''] < [''2'',''1''] True : Bool >
Logical Operators
Logical Operators are used to combine two or more conditions. Logical operators too return a Boolean value.
| Sr. No. | Operator | Description | Example |
|---|---|---|---|
| 1 | && | The operator returns true only if all the expressions specified return true | (10>5) && (20>5) returns True |
| 2 | || | The operator returns true if at least one of the expressions specified return true | (10 < 5) || (20 >5) returns True |
| 3 | not | The operator returns the inverse of the expression’s result. For E.g.: !(>5) returns false. | not (10 < 5) returns True |
| 4 | xor | The operator returns true only if exactly one input returns true. The operator returns false if both the expressions return true. | xor (10 > 5 ) (20 > 5) returns false |
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