Intel® Fortran Compiler 18.0 Developer Guide and Reference
A character expression consists of a character operator (//) that concatenates two operands of type character. The evaluation of a character expression produces a single value of that type.
The result of a character expression is a character string whose value is the value of the left character operand concatenated to the value of the right operand. The length of a character expression is the sum of the lengths of the values of the operands. For example, the value of the character expression 'AB'//'CDE' is 'ABCDE', which has a length of five.
Parentheses do not affect the evaluation of a character expression; for example, the following character expressions are equivalent:
('ABC'//'DE')//'F' 'ABC'//('DE'//'F') 'ABC'//'DE'//'F'
Each of these expressions has the value ' ABCDEF'.
If a character operand in a character expression contains blanks, the blanks are included in the value of the character expression. For example, 'ABC '//'D E'//'F ' has a value of 'ABC D EF '.