Language Reference

Constant Expressions

A constant expression is an expression in which each operation is intrinsic and each primary is one of the following:

• A constant or a subobject of a constant.
• An array constructor where each element and the bounds and strides of each implied-DO are expressions whose primaries are either constant expressions or implied-DO variables.
• A structure constructor where each component is a constant expression.
• An elemental intrinsic function reference where each argument is a constant expression.
• A transformational intrinsic function reference where each argument is a constant expression.
• A reference to the transformational intrinsic function NULL.
• A reference to an array inquiry function (except ALLOCATED), a numeric inquiry function, the BIT_SIZE function, the LEN function, or the KIND function. Each argument is either a constant expression or it is a variable whose properties inquired about are not assumed, not defined by an expression that is not a constant expression, and not definable by an ALLOCATE or pointer assignment statement.
• A constant expression enclosed in parentheses.

Any subscript or substring expression within the expression must be a constant expression.

Examples of Constant Expressions

-48.9
name('Pat','Doe')
TRIM('ABC    ')
(MOD(9,4)**3.5)