For Loop

[Tiya Kaitha]

I am new in java. And i am trying to understand nested for loop. But I have failed to do that. i just can not able to understand nested for loop. Here is a example.

public class Simple {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		for (int i = 1; i <= 5; i++) {

			for (int j = 1; j <= i; j++) {

				System.out.print(i);
			}
			System.out.println();
		}
	}

}

output:
1
22
333
4444
55555

Can anyone tell me elaborately how its working? In which manner its working?? please tell me. please ...

[Campbell Ritchie]

Welcome to the Ranch

Please avoid tabs for indenting, and use the code button. I have edited your post partially and you can see how much better it looks. If you use Eclipse (which is probably a bad idea at this beginning stage), you can set options to convert tabs to 4 spaces automatically. You are probably better off using a text editor, however.
I think you will only understand it if you go through it with a pencil and paper. Try this simplified version first, and you will see how a loop runs once.

public class Simple {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		int i = 3;
		for (int j = 1; j <= i; j++) {
			System.out.print(i);
		}
		System.out.println();
	}
}

Once you have worked out how that simpler version prints 3 thrice, you will find it easier to work out how the two loops work.

[Jeff Verdegan]

What part did you not understand? What did you expect that code to do?

Try this:

for (int i = 1; i <= 5; i++) {
  System.out.println("outer loop, i=" + i);
  for (int j = 1; j <= i; j++) {  
    System.out.println("inner loop, j=" + j);
  }  
}

Does that help? The outer loop says, "Do whatever is in my body, 5 times." The body is printing i and then running the inner loop, which says, "do whatever is in my body, 3 times. And that body is simply printing j.

[fred rosenberger]

nested for loops are like old-fashioned mechanical car odometers. The inner most one must go all the way around before the next outer one clicks over one...

[Jeff Verdegan]

fred rosenberger wrote:nested for loops are like old-fashioned mechanical car odometers. The inner most one must go all the way around before the next outer one clicks over one...

New-fangled odometers are like that too, 'cep'n that it's electronomical instead of mechanicated.

[Tiya Kaitha]

Thanks a lot...... my brain is working now...