moveZeros.js

function move_zeros(arrNum, isRight){
  isRight = typeof isRight === 'undefined' ? true : isRight;
  // console.log(arrNum);
  // console.log(isRight);
  var arrNumLength = arrNum.length;
  
  function eliminateZeros(element) {
      return element !== 0;
  }
  
  var arrayWithoutZeros = arrNum.filter(eliminateZeros);
  var arrNumLengthWithoutZeros = arrayWithoutZeros.length;
  var numberOfZerosToAdd = arrNumLength - arrNumLengthWithoutZeros;
  // console.log(arrayWithoutZeros);
  // console.log(numberOfZerosToAdd);

    var i = 1;
    var shiftZeros = arrayWithoutZeros;
    // console.log(shiftZeros);
    var tmpSwitchCaseArray = arrayWithoutZeros;
  switch(isRight) {
      case true:
          while (i <= numberOfZerosToAdd) {
              tmpSwitchCaseArray.push(0);
              i++;
          }
        break;
      case false:  
          while (i <= numberOfZerosToAdd) {
              tmpSwitchCaseArray.unshift(0);
              i++;
          }
        break;
          
  }
  return tmpSwitchCaseArray;
}

arrNum = [12, 0, 10, 0, 8, 12, 7, 6, 0, 4, 10, 12, 0];
move_zeros(arrNum);