A string is any succession of characters (printing or layout) enclosed in quotation marks (string quotes). Assuming that the hardware representations of the opening and closing quote symbols are distinguishable, occurrence of such marks must be properly paired within the string (but see Appendix B). A string is classed as an unconditional expression (Chapter 6), and its value is its location, but it may not be used as a LOCATION parameter. Procedures capable of selecting individual characters from a string should be designed so that characters are represented by the same integers values as are defined for literal constants.
String ::=
" sequence of characters with quotes matched "