Seek and Destroy pushes all elements

Tell us what’s happening:
Can someone please tell me why its pushing All the elements from arr1 into newArr instead of doing what I want it to do, and only push the elements that are not found in arr2, please explain my mistake.

Your code so far

function destroyer(arr) {
  var newArr=[];
  var arr1= arguments[0];
  var arr2=[];
  //get the second pair of args till the end:
  for (var i=1; i<arguments.length; i++){
  //if any of the elements in arr1 do not exist in arr2 push those elements into newArr
    for (var j=0; j<arr1.length; j++){
  if (arr2.indexOf(arr1[j]===-1)){
  // Tobdestroyed.filter(function(x){
  //   return x
  // })
destroyer([1, 2, 3, 1, 2, 3], 2, 3);

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Link to the challenge:

Edit: I now see I made a syntactic error, I have since fixed it, and solved this problem however I want to know why the error I made in typing (arr2.indexOf(arr1[j]===-1)) and putting the parenthesis in the wrong place, caused the statement to always evaluate to true, and push every element

When you write: arr1[j] === -1 each iteration was comparing the value of arr1[j] to -1. Since none of the arr1[j] values were equal to -1, then this comparison evaluated to false. The indexOf method was checking if any element in arr2 was the value false. The indexOf method returns a value of -1 if no index has the an element with the value specified, so your if statement was the equivalent of:

if (-1) {

All numeric values which are not the value 0 are truthy, so your if statement evaluated to true each time, so you pushed all the values of arr1 into newArr.

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