Summary -
In this topic, we described about the Selective Programming Construction with detailed example.
Selective programming construction involves making the set of statements runs in conditional/selective manner. In selective programming construction, the statements execution decides by a condition.
Every condition has two selection flows (either condition true flow or condition false flow).Single line conditional statements are the part of selective programming construction.
COBOL has a below statements that are part of selective programming -
| Statement | Description |
|---|---|
| IF | Evaluates a condition and decides the program flow depending on the evaluation. |
| EVALUATE | Provides a multi selection control during the program execution. |
Example:
Example with a combination of IF and EVALUATE statements.
Code:
IDENTIFICATION DIVISION.
PROGRAM-ID. IFCOND.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 STUDENT-DETAILS.
02 STD-NUM PIC 9(03).
02 STD-NAME.
03 STD-NAME-INIT PIC X(01).
88 STD-NAME-VALID VALUE 'A' THRU 'Z'.
03 STD-NAME-REST PIC X(14).
02 STD-GENDER PIC X(01).
88 VALID-GENDER VALUE 'M' 'F'.
02 STD-MARKS PIC 9(03).
88 FIRST-CLASS VALUE 060 THRU 100.
88 SECOND-CLASS VALUE 050 THRU 059.
88 THIRD-CLASS VALUE 035 THRU 049.
88 FAIL VALUE 000 THRU 034.
PROCEDURE DIVISION.
ACCEPT STD-NUM.
ACCEPT STD-NAME.
ACCEPT STD-MARKS.
DISPLAY 'STUDENT DETAILS....'.
DISPLAY 'STUDENT NUMBER : ' STD-NUM.
* SIMPLE IF CONDITION
IF STD-NAME-VALID
DISPLAY 'STUDENT NAME : ' STD-NAME
END-IF.
* IF ELSE CONDITION
IF VALID-GENDER
DISPLAY 'STUDENT GENDER : ' STD-GENDER
ELSE
DISPLAY 'STUDENT GENDER GIVEN WAS INVALID'
END-IF.
* EVALUATE
EVALUATE STD-MARKS
WHEN 60 THRU 100
DISPLAY 'STUDENT GOT FIRST CLASS '
WHEN 50 THRU 59
DISPLAY 'STUDENT GOT SECOND CLASS '
WHEN 35 THRU 49
DISPLAY 'STUDENT GOT THIRD CLASS '
WHEN OTHER
DISPLAY 'STUDENT FAILED '
END-EVALUATE.
STOP RUN.