code: function arraySubtraction(arrA, arrB) {
  	arrA = arrA.slice();
  	for (let i = 0; i < arrB.length; ++i) {
  		arrA = arrA.filter(function (value) {
  			return value !== arrB[i];
  		});
  	}
  	return arrA;
  }
docs: Array subtraction.
  
  @param  {Array} arrA The minuend array.
  @param  {Array} arrB The subtrahend array.
  
  @return {Array}      The difference array.