Return string from iterative loop (Not using System.out.println)

Hello,

I am trying to figure out how to return a string from a iterative loop.

I know how to code it using system.out.println, but I need to return the whole value as a string. Below is the code for the println version of the code.

for (int i = 0; i < 5; i++) {
	  for (int j = 0; j <= i; j++) {
	    	System.out.print("*");
	  }
	    	System.out.println();
}

It outputs this:

*
**
***
****
*****

However I need to return that whole output as a string, not using the println method. This is what I have so far, but it hits the return and breaks before it can continue to loop. (At least that's what I think).

//Size is a integer being passed in, for this example lets say 5 to match above.
	    public static String triangle(int size){
	    	
                String s = "";
	    	
	        for (int i = 0; i < size; i++) {
	        	   s = "";
	        	   for (int j = 0; j <= i; j++) {
	        	      s = "*" + "\n";
	        	   }	   
	        }
	    return s;
	    }

Thanks for the advice/guidance.