MODULE 7 · WORKING WITH TEXT · 6/8

String intrinsic functions

12 min30 XPExercise

STRING, UNSTRING and INSPECT are statements: they change fields in place. Intrinsic functions are different: they take arguments and return a new value, which you can display, move, compare or pass to another function. You call them with the word FUNCTION:

       IDENTIFICATION DIVISION.
       PROGRAM-ID. STRFUNC.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  WS-IN        PIC X(20) VALUE "   Grace Hopper".
       01  WS-OUT       PIC X(20).
       01  WS-LEN       PIC 9(3).
       PROCEDURE DIVISION.
           DISPLAY "[" FUNCTION TRIM(WS-IN) "]"
           DISPLAY "[" FUNCTION TRIM(WS-IN LEADING) "]"
           DISPLAY "[" FUNCTION TRIM(WS-IN TRAILING) "]"
           DISPLAY "[" FUNCTION UPPER-CASE(WS-IN) "]"
           MOVE FUNCTION LOWER-CASE(FUNCTION TRIM(WS-IN)) TO WS-OUT
           DISPLAY "[" WS-OUT "]"
           DISPLAY "[" FUNCTION REVERSE("STRESSED") "]"
           MOVE FUNCTION LENGTH(WS-IN) TO WS-LEN
           DISPLAY "FIELD LENGTH: " WS-LEN
           MOVE FUNCTION LENGTH(FUNCTION TRIM(WS-IN)) TO WS-LEN
           DISPLAY "TEXT LENGTH:  " WS-LEN
           DISPLAY "[" FUNCTION CONCATENATE(
               FUNCTION TRIM(WS-IN) " (" "ADMIRAL" ")") "]"
           STOP RUN.

Output:

[Grace Hopper]
[Grace Hopper     ]
[   Grace Hopper]
[   GRACE HOPPER     ]
[grace hopper        ]
[DESSERTS]
FIELD LENGTH: 020
TEXT LENGTH:  012
[Grace Hopper (ADMIRAL)]

Function	Returns
`TRIM(x)`	`x` without leading and trailing spaces. `TRIM(x LEADING)` or `TRIM(x TRAILING)` trims one side only
`UPPER-CASE(x)`, `LOWER-CASE(x)`	`x` with letters converted
`REVERSE(x)`	`x` backwards
`LENGTH(x)`	the number of characters in `x`
`CONCATENATE(a b ...)`	the arguments joined together

Lengths: field versus text

FUNCTION LENGTH(WS-IN) is the declared size of the field, 20, no matter what it holds. To measure the text inside, trim it first: FUNCTION LENGTH(FUNCTION TRIM(WS-IN)). For trailing spaces only (keep an intentional indent), use TRIM(WS-IN TRAILING).

Move numeric results into a field of your own before displaying them, as the example does with WS-LEN. Displayed directly, a function result's format depends on the compiler.

Functions nest

A function call can appear wherever a value of its type is allowed, including as another function's argument. FUNCTION LOWER-CASE(FUNCTION TRIM(WS-IN)) trims first, then lower-cases the result. A function only produces a value: it can never be the target of a MOVE. To change part of the result, move it into a field first and work on the field.

Functions versus statements

Most of this overlaps with earlier lessons. UPPER-CASE does what INSPECT ... CONVERTING does, and CONCATENATE does what STRING does. Functions are shorter and read more naturally. The statements are older, work on every compiler, and give you control that functions do not (pointers, overflow detection, counts).

Compiler support

UPPER-CASE, LOWER-CASE, REVERSE and LENGTH have been standard since 1989. TRIM arrived later, so older code does the same job with INSPECT and reference modification loops. CONCATENATE is a newer addition that not every mainframe compiler supports: GnuCOBOL has it, but check your shop's compiler before relying on it. STRING always works.

On the job

Names and addresses from online channels arrive in any case, with stray spaces. Standardising them (trimmed, one consistent case) before you store or compare them saves you from duplicate customers such as grace hopper and GRACE HOPPER.

Your task

Names typed into the online account-opening form arrive in any case with stray spaces around them. Read one line (WS-IN, PIC X(40)) holding a first and last name, e.g. gRACE hopper, and display:

UPPER: GRACE HOPPER
NAME: Grace Hopper
LENGTH: 12

UPPER is the trimmed name in capitals.
NAME is the trimmed name in title case: the first letter of each word upper case, everything else lower case. Words are separated by single spaces.
LENGTH is the length of the trimmed name, as 2 digits.

The starter declares WS-NAME, a loop counter WS-I, WS-LEN and WS-PREV (the previous character).

← Counting and replacing with INSPECT Parsing CSV and NUMVAL →

Run your program to see its output here. The first visible test's input and datasets are used.

Submit to grade your program against every test.