freecodecamp: Seek and Destroy

removeItems.md

Description

You will be provided with an initial array (the first argument in the destroyer function), followed by one or more arguments. Remove all elements from the initial array that are of the same value as these arguments.
Note: You have to use the arguments object.

Tests

tests:
  - text: <code>destroyer([1, 2, 3, 1, 2, 3], 2, 3)</code> should return <code>[1, 1]</code>.
    testString: assert.deepEqual(destroyer([1, 2, 3, 1, 2, 3], 2, 3), [1, 1]);
  - text: <code>destroyer([1, 2, 3, 5, 1, 2, 3], 2, 3)</code> should return <code>[1, 5, 1]</code>.
    testString: assert.deepEqual(destroyer([1, 2, 3, 5, 1, 2, 3], 2, 3), [1, 5, 1]);
  - text: <code>destroyer([3, 5, 1, 2, 2], 2, 3, 5)</code> should return <code>[1]</code>.
    testString: assert.deepEqual(destroyer([3, 5, 1, 2, 2], 2, 3, 5), [1]);
  - text: <code>destroyer([2, 3, 2, 3], 2, 3)</code> should return <code>[]</code>.
    testString: assert.deepEqual(destroyer([2, 3, 2, 3], 2, 3), []);
  - text: <code>destroyer(["tree", "hamburger", 53], "tree", 53)</code> should return <code>["hamburger"]</code>.
    testString: assert.deepEqual(destroyer(["tree", "hamburger", 53], "tree", 53), ["hamburger"]);
  - text: <code>destroyer(["possum", "trollo", 12, "safari", "hotdog", 92, 65, "grandma", "bugati", "trojan", "yacht"], "yacht", "possum", "trollo", "safari", "hotdog", "grandma", "bugati", "trojan")</code> should return <code>[12,92,65]</code>.
    testString: assert.deepEqual(destroyer(["possum", "trollo", 12, "safari", "hotdog", 92, 65, "grandma", "bugati", "trojan", "yacht"], "yacht", "possum", "trollo", "safari", "hotdog", "grandma", "bugati", "trojan"), [12,92,65]);

Solution

My Soln:

function destroyer(arr) {
  // Remove all the values
  let removeList=[...arguments].slice(1);
  return arr.filter(e=>removeList.indexOf(e)===-1);
}

destroyer([1, 2, 3, 1, 2, 3], 2, 3);

Offical soln:

function destroyer(arr) {
  var hash = Object.create(null);
  [].slice.call(arguments, 1).forEach(function(e) {
    hash[e] = true;
  });
  // Remove all the values
  return arr.filter(function(e) { return !(e in hash);});
}

Further readings

9 Ways to Remove Elements From A JavaScript Array - Plus How to Safely Clear JavaScript Arrays
Includes() vs indexOf() in JavaScript
in operator - MDN