I have a task to remove false, null, 0, "", undefined, and NaN elements from an given array. I worked on a solution which removes all except null. Anyone can explain why? Here's the code:

function bouncer(arr) {

var notAllowed = ["",false,null,0,undefined,NaN];

  for (i = 0; i < arr.length; i++){

      for (j=0; j<notAllowed.length;j++) {

         arr = arr.filter(function(val) {

               return val !== notAllowed[j];

              });

  }

 }

return arr;

}



bouncer([1,"", null, NaN, 2, undefined,4,5,6]);