ISRO2007-23

Question

Study the following program

//precondition: x>=0
public void demo(int x)
{
    System.out.print(x % 10); 
    if (x % 10 != 0)
    {
        demo(x/10);
    }
    System.out.print(x%10);
}

Which of the following is printed as a result of the call demo $(1234)$?

• A. $1441$
• B. $3443$
• C. $12344321$
• D. $43211234$

Comments

it will print "4321001234" because demo(0) function call is also executing...

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At demo(0) loop terminate by giving two zero as output.. I think so..

Answer 1

Option D

it Prints 43211234 as output

Comments

yeah its 4321001234 and not 43211234.

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It's 4321001234 but i don't know why, please explain.

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original question is 

//precondition: x>=0
public void demo(int x)
{
    System.out.print(x % 10);     
    if (x / 10 != 0)

    {
        demo(x/10);
    }
    System.out.print(x%10);
}

Answer 2

https://ide.geeksforgeeks.org/ifEWm3t0nr

Visit this link to run and check the program.

Answer is D

Comments

if (x%10 != 0) then o/p 4321001234

if (x/10 != 0) then o/p 43211234

Answer 3

It prints 4321001234