Using national-character figurative constants

You can use the figurative constants QUOTE, SPACE, HIGH-VALUE, LOW-VALUE, or ZERO in a context that requires national characters, such as a MOVE statement, an implicit move, or a relation condition that has national operands. In these contexts, the figurative constant represents a national-character (UTF-16) value.

When you use the figurative constant QUOTE in a context that requires national characters, and the QUOTE compiler option is in effect, its value is NX'0022'. If the APOST compiler option is in effect, its value is NX'0027'.

When you use the figurative constant HIGH-VALUE in a context that requires national characters, its value is NX'FFFF'. When you use LOW-VALUE in a context that requires national characters, its value is NX'0000'.

Restrictions: You must not use HIGH-VALUE or the value assigned from HIGH-VALUE in a way that results in conversion of the value from one data representation to another (for example, between USAGE DISPLAY and USAGE NATIONAL). X'FF' (the value of HIGH-VALUE in an alphanumeric context when the EBCDIC collating sequence is being used) does not represent a valid EBCDIC character, and NX'FFFF' does not represent a valid national character. Conversion of such a value to another representation results in a substitution character being used (not X'FF' or NX'FFFF'). Consider the following example:

01 natl-data  PIC NN  Usage National.
01 alph-data  PIC XX.
. . .
    MOVE HIGH-VALUE TO natl-data, alph-data
    IF natl-data = alph-data. . .

The IF statement above evaluates as false even though each of its operands was set to HIGH-VALUE. Before an elementary alphanumeric operand is compared to a national operand, the alphanumeric operand is treated as though it were moved to a temporary national data item, and the alphanumeric characters are converted to the corresponding national characters. When X'FF' is converted to UTF-16, however, the UTF-16 item gets a substitution character value and so does not compare equally to NX'FFFF'.