Intel® Fortran Compiler 17.0 Developer Guide and Reference
Statement: Assigns a value to a nonpointer variable. In the case of pointers, intrinsic assignment is used to assign a value to the target associated with the pointer variable. The value assigned to the variable (or target) is determined by evaluation of the expression to the right of the equal sign.
variable=expression
variable |
Is the name of a scalar or array of intrinsic or derived type (with no defined assignment). The array cannot be an assumed-size array, and neither the scalar nor the array can be declared with the PARAMETER or INTENT(IN) attribute. |
expression |
Is of intrinsic type or the same derived type as variable. Its shape must conform with variable. If necessary, it is converted to the same type and kind as variable. |
Before a value is assigned to the variable, the expression part of the assignment statement and any expressions within the variable are evaluated. No definition of expressions in the variable can affect or be affected by the evaluation of the expression part of the assignment statement.
When the run-time system assigns a value to a scalar integer or character variable and the variable is shorter than the value being assigned, the assigned value may be truncated and significant bits (or characters) lost. This truncation can occur without warning, and can cause the run-time system to pass incorrect information back to the program.
If the variable is a pointer, it must be associated with a definable target. The shape of the target and expression must conform and their type and kind parameters must match.
If the !DIR$ NOSTRICT compiler directive (the default) is in effect, then you can assign a character expression to a noncharacter variable, and a noncharacter variable or array element (but not an expression) to a character variable.
REAL a, b, c
LOGICAL abigger
CHARACTER(16) assertion
c = .01
a = SQRT (c)
b = c**2
assertion = 'a > b'
abigger = (a .GT. b)
WRITE (*, 100) a, b
100 FORMAT (' a =', F7.4, ' b =', F7.4)
IF (abigger) THEN
WRITE (*, *) assertion, ' is true.'
ELSE
WRITE (*, *) assertion, ' is false.'
END IF
END
! The program above has the following output:
! a = .1000 b = .0001 a > b is true.
! The following code shows legal and illegal
! assignment statements:
!
INTEGER i, j
REAL rone(4), rtwo(4), x, y
COMPLEX z
CHARACTER name6(6), name8(8)
i = 4
x = 2.0
z = (3.0, 4.0)
rone(1) = 4.0
rone(2) = 3.0
rone(3) = 2.0
rone(4) = 1.0
name8 = 'Hello,'
! The following assignment statements are legal:
i = rone(2); j = rone(i); j = x
y = x; y = z; y = rone(3); rtwo = rone; rtwo = 4.7
name6 = name8
! The following assignment statements are illegal:
name6 = x + 1.0; int = name8//'test'; y = rone
END