Array Weird Results in Cartesian product javasccript

Question

I am stuck in the following code, i am getting all possible combination of layers from Photoshop. here in this example i have a group with three layers and (blue,purple,gold). I am taking these layers as array and the calling this combine function.

The problem is that every time a new combination is pushed in ""allCombination" array, the all combination array's previous element also turned to new element. In short if i had pushed [blue,purple] at allCombination[0] but when a push the second array combination as [blue,gold] in allCombination[1] The whole array "allCombination" become [blue,gold],[blue,gold]

var allCombinations = [];

var result = [];
result.length = 2; //n=2

function combine(input, len, start) {
  if(len === 0) {
    allCombinations.push(result); //process here the result
    $.writeln (allCombinations)
    return;
  }
  for (var i = start; i <= input.length - len; i++) {
    result[result.length - len] = input[i];
    combine(input, len-1, i+1 );
  }
}

var array = ["Blue", "purple", "gold"];    
  
combine( array, result.length, 0);

alert(allCombinations);

/////////////////////////////////

The above code gives following result

Blue,purple
Blue,gold,Blue,gold
purple,gold,purple,gold,purple,gold

You only have one `result` array, so you keep modifying that same one over and over. — Robby Cornelissen, Apr 11 '22 at 01:35
but i am pushing each time that same result in global combination array. why the global value is changing — Hostile Se H Tak, Apr 11 '22 at 01:45
Pushing does not create a copy. You repeatedly push a reference to the same array. — Robby Cornelissen, Apr 11 '22 at 01:48
Thanks a lot @Robby Cornelissen this was my first question here on stackOverflow and you promptly, helped me out thanks — Hostile Se H Tak, Apr 11 '22 at 01:53

Array Weird Results in Cartesian product javasccript

0 Answers0