s is a bit string, character string, or picture value. If s is not a string, it is converted to a bit string if it is binary or to a character string if it is decimal. i is an integer value indicating the first bit (if s is a bit string) or character of a substring within s; and j is an integer value indicating the length of the substring within s.
Description
The SUBSTR function returns a string that is a copy of a part of the string s starting at the character specified by i for a length specified by j. If j is not given, j = LENGTH(s)-i+1, that is, the remainder of the string s.
The program is in error if i < 1 or (i + j -1) > LENGTH(s) or j < 0. If the program is compiled with subscript checking enabled, these errors result in the ERROR condition; otherwise, these errors produce unpredictable results.
For a description of the SUBSTR function's use as a pseudo-variable, and for the description of the ASSIGNMENT statement, see the section Assignment in the chapter Statements.