QBASIC – Even or Odd using FUNCTION Procedure

Table of Contents

• Overview
• Check Even or Odd Without Parameters
• Check Even or Odd With Parameters
• Output – Even or Odd using Function Procedure
• Explanation

Overview

Below is a QBASIC program to find if a number entered by the user is even or odd using FUNCTION Procedure i.e., FUNCTION…END FUNCTION.

Using SUB…END SUB: QBASIC – Even or Odd Using SUB Procedure

Check Even or Odd Without Parameters

REM Program to input a number and check if it is even or odd
DECLARE FUNCTION EVENORODD$
CLS
PRINT "The number is "; EVENORODD$
END
FUNCTION EVENORODD$
  INPUT "Enter a number";a
  IF a MOD 2 = 0 THEN
    result$ = "even"
  ELSE 
    result$ = "odd"
  END IF
  EVENORODD$ = result$
END FUNCTION

Check Even or Odd With Parameters

REM Program to input a number and check if it is even or odd
DECLARE FUNCTION EVENORODD$(a)
CLS
INPUT "Enter a number";a
PRINT "The number is "; EVENORODD$(a)
END
FUNCTION EVENORODD$(a)
  IF a MOD 2 = 0 THEN
    result$ = "even"
  ELSE 
    result$ = "odd"
  END IF
  EVENORODD$ = result$
END FUNCTION

Output – Even or Odd using Function Procedure

Explanation

Notice the dollar ($) sign at the end of the function name. The dollar($) sign represent the string in QBASIC. Here, the dollar sign at the end of the function name is used to return any string value from the function procedure to any main module. As the program requires to display either even or odd from the submodule to the main module, we are using EVENORODD$ = result$ to return the value of result$ (even or odd) to the main module.