How to resolve the algorithm Determine if a string is numeric step by step in the COBOL programming language

Published on 12 May 2024 09:40 PM
#Cobol

How to resolve the algorithm Determine if a string is numeric step by step in the COBOL programming language

Table of Contents

Problem Statement

Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.

Let's start with the solution:

Step by Step solution about How to resolve the algorithm Determine if a string is numeric step by step in the COBOL programming language

Source code in the cobol programming language

        program-id. is-numeric.
        procedure division.
        display function test-numval-f("abc") end-display
        display function test-numval-f("-123.01E+3") end-display
        if function test-numval-f("+123.123") equal zero then
            display "is numeric" end-display
        else
            display "failed numval-f test" end-display
        end-if
        goback.


       IDENTIFICATION DIVISION.
       PROGRAM-ID. Is-Numeric.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  Numeric-Chars      PIC X(10) VALUE "0123456789".
       
       01  Success            CONSTANT 0.
       01  Failure            CONSTANT 128.

       LOCAL-STORAGE SECTION.
       01  I                  PIC 99.

       01  Num-Decimal-Points PIC 99.
       01  Num-Valid-Chars    PIC 99.

       LINKAGE SECTION.
       01  Str                PIC X(30). 

       PROCEDURE DIVISION USING Str.
           IF Str = SPACES
               MOVE Failure TO Return-Code
               GOBACK
           END-IF

           MOVE FUNCTION TRIM(Str) TO Str

           INSPECT Str TALLYING Num-Decimal-Points FOR ALL "."
           IF Num-Decimal-Points > 1
               MOVE Failure TO Return-Code
               GOBACK
           ELSE
               ADD Num-Decimal-Points TO Num-Valid-Chars
           END-IF

           IF Str (1:1) = "-" OR "+"
               ADD 1 TO Num-Valid-Chars
           END-IF
           
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 10
               INSPECT Str TALLYING Num-Valid-Chars
                   FOR ALL Numeric-Chars (I:1) BEFORE SPACE
           END-PERFORM

           INSPECT Str TALLYING Num-Valid-Chars FOR TRAILING SPACES

           IF Num-Valid-Chars = FUNCTION LENGTH(Str) 
               MOVE Success TO Return-Code
           ELSE
               MOVE Failure TO Return-Code
           END-IF

           GOBACK
           .

You may also check:How to resolve the algorithm Sorting algorithms/Bead sort step by step in the Pascal programming language
You may also check:How to resolve the algorithm Luhn test of credit card numbers step by step in the REXX programming language
You may also check:How to resolve the algorithm Hello world/Text step by step in the Visual Basic programming language
You may also check:How to resolve the algorithm Odd word problem step by step in the Haskell programming language
You may also check:How to resolve the algorithm Xiaolin Wu's line algorithm step by step in the C fast fixed-point programming language