COBOL by Example: String Handling

COBOL 2002

Manipulating strings with STRING for concatenation, UNSTRING for splitting text by delimiters, INSPECT for counting and replacing characters, handling fixed-width fields with DELIMITED BY clauses, and formatting data for reports.

Code

       IDENTIFICATION DIVISION.
       PROGRAM-ID. STRINGS.
       
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  F-NAME      PIC X(10) VALUE "John".
       01  L-NAME      PIC X(10) VALUE "Doe".
       01  FULL-NAME   PIC X(30) VALUE SPACES.
       01  SENTENCE    PIC X(50) VALUE "COBOL IS FUN".
       01  COUNT-O     PIC 99 VALUE 0.
       
       PROCEDURE DIVISION.
           *> Concatenation
           STRING F-NAME DELIMITED BY SPACE
                  " " DELIMITED BY SIZE
                  L-NAME DELIMITED BY SPACE
                  INTO FULL-NAME.
           DISPLAY "Full Name: " FULL-NAME.
           
           *> Counting characters
           INSPECT SENTENCE TALLYING COUNT-O FOR ALL "O".
           DISPLAY "Count of 'O': " COUNT-O.
           
           *> Replacing characters
           INSPECT SENTENCE REPLACING ALL "FUN" BY "COOL".
           DISPLAY "New Sentence: " SENTENCE.
           STOP RUN.

Explanation

COBOL provides specialized verbs for string processing that are powerful and efficient. The STRING verb concatenates multiple strings into one, handling delimiters automatically. The UNSTRING verb does the reverse, parsing a string into multiple fields.

The INSPECT verb is a workhorse for string validation and manipulation. It can count occurrences of a character (TALLYING) or replace characters (REPLACING). This is often used to sanitize input or format data for output.

These verbs operate on fixed-length buffers, so you often use the DELIMITED BY clause to ignore trailing spaces. This is a common pattern in COBOL, where string variables are typically fixed-width fields padded with spaces.

STRING: Concatenates multiple strings into one.
UNSTRING: Splits a string into multiple parts based on delimiters.
INSPECT: Used for counting occurrences or replacing characters.

Code Breakdown

13

STRING ... INTO FULL-NAME. Combines "John", a space, and "Doe". DELIMITED BY SPACE ensures we don't include the trailing spaces from the fixed-width fields.

20

INSPECT ... TALLYING. Scans the variable SENTENCE and counts every instance of the letter "O", storing the result in COUNT-O.

24

INSPECT ... REPLACING. Modifies the variable in-place, changing "FUN" to "COOL". Note that the replacement string must be the same length for simple replacements.

14

DELIMITED BY SIZE. Means "take the whole string".

Samplebadu

COBOL by Example: String Handling

Code

Explanation

Code Breakdown