CODEWITHSUNDEEP
javarecursion
Devendra Kushwah
Devendra Kushwah

Reputation: 31

Can anyone explain how this code prints 1 to 10?

Can anyone explain how this code prints 1 to 10???

class demo
{

    public static void main(String[] args) 
    {
        display(10);    
    }
    private static void display(int n) 
    {
        if (n > 1) 
        {
            display(n - 1);
        }
        System.out.println(n);
    }
}

Upvotes: 0

Views: 67

Answers (2)

Shubham Singh
Shubham Singh

Reputation: 211

It's a recursive call to display method. Here the argument value passed to display method is stored in a stack. when the if condition fails then the value of n if poped from stack and printed by line "System.out.println(n)". In other words, Every time display method called by passing a number, the number will be stored in a stack so that when code will come out of recursion, it will use that number from stack.

Doing the dry run you can see when the value 1 is passed to display method the if condition fails and the next line prints the value 1 then 2 will be printed which was in stack and so on it will print up to 10 which is the first value passed.

Upvotes: 2

C4rbyn3m4n
C4rbyn3m4n

Reputation: 1

So the main method runs the display method and passes a value of 10. Then, the value is checked to see if it is greater than 1 (which it is). Next. the display method is called again with a value of n-1, which is 9 in this case. Lastly, 10 is printed out.

Now 9 goes through the same cycle. 9 is greater than 1 and display is called with a value of n-1, which is now 8. 9 is printed out and now 8 goes through the display method. This continues to happen until the value is 1 in which case 1 is not greater than 1 and 1 is printed out and the program exits.

This is called a recursive method if you would like to look into it more.

Upvotes: 0

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