rotate a 2D (2 dimensional) array clockwise (right) by 90 degrees in JavaScript

rotateArrayRight.js

function rotateArrayRight( arr ){
	// rotates a 2D array 90 degrees to the right (clockwise)

	var newarr = [];

	for( var x = 0; x < arr[0].length; x++ ){
	  newarr[x] = [];
	  for( var y = arr.length - 1; y >= 0; y-- ){
	    newarr[x].push( arr[y][x] );
	  }
	}

	return newarr;

}

can you please explain the code why you have used arr[0].length

@nishanthreddy114 to get the length of the first row