An operator is a symbol that explains the compiler to do specific mathematical or logical calculations. We will also discuss operators precedence. Fortran provides the following operator types:
Operator | Description | Meaning |
+ | This Addition operator is used to add two operands | Add X with Y |
- | This Subtraction operator is used to subtract second operator from the first one | Subtract Y from X |
* | This Multiplication operator is used to multiplies both operands | Multiply X with Y |
/ | This Division operator is used to divides numerator by denominator | Divide X with Y |
** | This Exponentiation operator is used to raises one operand to the power of the other | X with Y as Power (Exponentiation) |
Operator | Description | Demo |
.AND. | It is called AND operator. If both operands are non-zero then returns true | Logical conjunction |
.OR. | It is called OR operator to use if any of two operands is not zero then it returns true | Logical disjunction |
.XOR | It is called exclusive OR, The negation of OR operation result. | Logical exclusive OR |
.NOT. | It is called NOT operator to reverse the logical state of its operand. | Logical negation |
.EQV. | It is called EQUIVALENT operator to check equivalence of two operands. | Logical equivalence |
.NEQV. | It is called the NON-EQUIVALENT operator to check the non-equivalence of two operands. | Logical nonequivalence |
Operator | Equivalent Operator | Description | Meaning |
!= | .NE. | To check if values of two operands are equal or not. If no then return true | X is not equal to Y |
== | .EQ. | To check if values of two operands are equal or not. If yes then return true | X is Equal to Y |
> | .GT. | To check whether the value of left operand is greater than of the right. If yes then returns true | X is greater than Y |
< | .LT. | To check whether the value of left operand is lesser than of the right. If yes then returns true | X is less tah Y |
<= | .LE. | To check whether the value of left operand is lesser than or equal to than the right. If yes then return true | X is less than or equal to Y |
>= | .GE. | To check whether the value of left operand is greater than or equal to than the right. If yes then return true
| X is greater than or equal to Y |
Here, x is assigned 47, not 119 because multiplication has higher precedence than addition.
In the second example a is assigned 1 and not 64 because the Exponentiation operator has higher precedence than the Division one.
The following table represents all the operators’ precedence that is supported by Fortran, either from left to right or right to left.
Category | Precedence Index | Operator | Associativity |
Logical NOT and negative sign | 1st | .not. (-) | Left to right |
Exponentiation | 2nd | ** | Left to right |
Multiplicative | 3rd | */ | Left to right |
Additive | 4th | +- | Left to right |
Equality | 6th | == /= | Left to right |
Assignment | 9th | = | Right to Left |
Logical AND | 7th | .and. | Left to right |
Logical OR | 8th | .or. | Left to right |
Relational | 5th | < <= > >= | Left to right |