Character Expressions

  The character operator // is used to concatenate, or join, two character strings. It is, in fact, the only character operator that Fortran provides. Thus:

'CUP' // 'BOARD' $\Longrightarrow$ 'CUPBOARD'

The length of the result is just the sum of the lengths of the operands. Parentheses may be used in character expressions but make no difference to the result. Note that any embedded or trailing blanks (spaces) will be reproduced exactly in the resulting string.

The general form of a character-expression is thus:
character-operand
or character-expression // character-operand
where character-operand can be any of the following:

• character constant (literal or named),
• character variable,
• character array element,
• character substring,
• character function reference.

There is one special restriction on character concatenation in procedures: a passed-length dummy argument can only be an operand of the concatenation operator in an assignment statement. This seemingly arbitrary rule allows the compiler to determine how much work-space is required.