Grade-10 Ch-10: Review of built in function in QBASIC Lab

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Lab Work Questions on User-Defined Functions in QBasic

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Question 1: Write a program using a user-defined function to calculate the area of a rectangle.

Answer:

DECLARE FUNCTION Aare(length, breadth)

CLS

REM Main Program
INPUT "Enter the length of the rectangle: ", length
INPUT "Enter the breadth of the rectangle: ", breadth

REM Call the function
result = Area(length, breadth)
PRINT "The area of the rectangle is: "; result
END

REM Define the function to calculate area
FUNCTION Area(length, breadth)
    Area = length * breadth
END FUNCTION

Explanation:

• A function Area is defined to calculate the area of a rectangle using the formula Area = length * breadth.
• The function is called in the main program to compute and print the area.

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Question 2: Write a program using a user-defined function to calculate the perimeter of a rectangle.

Answer:

DECLARE FUNCTION Perimeter (length, breadth)

CLS

REM Main Program
INPUT "Enter the length of the rectangle: ", length
INPUT "Enter the breadth of the rectangle: ", breadth

REM Call the function
result = Perimeter(length, breadth)
PRINT "The perimeter of the rectangle is: "; result
END

REM Define the function to calculate perimeter
FUNCTION Perimeter(length, breadth)
    Perimeter = 2 * (length + breadth)
END FUNCTION

Explanation:

• The Perimeter function calculates the perimeter using the formula 2 * (length + breadth).
• The function is then called to compute and display the perimeter.

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Question 3: Write a program using a user-defined function to check if a number is a palindrome.

Answer:

DECLARE Function Ispalindrome$(number)

CLS

REM Main Program
INPUT "Enter a number: ", num

REM Call the function
    PRINT num; Ispalindrome$
END
REM Define the function to check palindrome
FUNCTION IsPalindrome(number)
    original = number
    reverse = 0
    WHILE number <> 0
        remainder = number MOD 10
        reverse = reverse * 10 + remainder
        number = INT(number / 10)
    WEND
    
    IF original = reverse THEN
        IsPalindrome$ = "Palindrome"
    ELSE
        IsPalindrome$ = "Not palindrome"
    END IF
END FUNCTION

Explanation:

• The function IsPalindrome checks if the number is the same when reversed. If true, it returns TRUE; otherwise, it returns FALSE.
• The main program calls this function and displays the result.

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Question 4: Write a program using a user-defined function to check if a string is a palindrome.

Answer:

DECLARE FUNCTION IsStringPalindrome$(str$)

CLS

REM Main Program
INPUT "Enter a string: ", userString

REM Call the function
    PRINT userString; IsStringPalindrome$;
END
REM Define the function to check palindrome string
FUNCTION IsStringPalindrome$(str$)
    len = LEN(str$)
    FOR i = 1 TO len

    rev$=UCASE$(MID$(str$,i,1)+rev$

NEXT i

IF str$=rev$ THEN

    IsStringPalindrome$=" String Palindrome"

ELSE

 IsStringPalindrome$=" String not Palindrome"
END IF
END FUNCTION

Explanation:

• The function IsStringPalindrome checks if the string is the same when read forwards and backwards.
• The program calls this function and prints whether the string is a palindrome.

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Question 5: Write a program using a user-defined function to find the factorial of a number.

Answer:

DECLARE FUNCTION Factorial(n)

CLS

REM Main Program
INPUT "Enter a number: ", n

REM Call the function
result = Factorial(n)
PRINT "The factorial of "; n; " is: "; result
END
REM Define the function to calculate factorial
FUNCTION Factorial(num)
    fact = 1
    FOR i = 1 TO num
        fact = fact * i
    NEXT i
    Factorial = fact
END FUNCTION

Explanation:

• The function Factorial calculates the factorial of a number using a FOR-NEXT loop.
• The main program calls this function to calculate and display the factorial.

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Question 6: Write a program using a user-defined function to check whether a number is even or odd.

Answer:

DECLARE FUNCTION IsEvenOrOdd$(number)

CLS

REM Main Program
INPUT "Enter a number: ", number

REM Call the function
result$ = IsEvenOrOdd$(number)
PRINT "The number "; number; " is "; result$
END
REM Define the function to check even or odd
FUNCTION IsEvenOrOdd(num)
    IF num MOD 2 = 0 THEN
        IsEvenOrOdd$ = "Even"
    ELSE
        IsEvenOrOdd$ = "Odd"
    END IF
END FUNCTION

Explanation:

• The function IsEvenOrOdd checks if the number is divisible by 2 (MOD 2 = 0) to determine if it's even or odd.
• The main program calls the function and displays whether the number is even or odd.

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Summary of User-Defined Functions:

1. Area function: Calculates the area of a rectangle.
2. Perimeter function: Calculates the perimeter of a rectangle.
3. IsPalindrome function: Checks if a number is a palindrome.
4. IsStringPalindrome function: Checks if a string is a palindrome.
5. Factorial function: Calculates the factorial of a number.
6. IsEvenOrOdd function: Checks if a number is even or odd.

These questions are designed to help students practice creating and using user-defined functions in QBasic to solve various problems.