how to remove all elements from the initial array that are of the same value as these arguments?

Question

I wrote this code to remove all 2 and 3 from the array and wanted to have this result:

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

but instead the result is:

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

This is function code:

function destroyer(arr) {
  var a = Array.prototype.slice.call(arguments);
  var b = a[0];

  for (var i = 1; i < a.length; i++) {
    if (b.indexOf(a[i]) !== -1) {
      b.splice(a[i], 1);
    }
  }

  return b;
}

console.log(destroyer([1, 2, 3, 1, 2, 3], 2, 3));

void · Answer 1 · 2018-02-21T07:17:03.370

1

You can do this using .filters

b.filter(el => !a.includes(el));

Check the complete code below:

function destroyer(a, ...b) {
  a = a.filter(el => !b.includes(el));
  console.log(a);
}

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

edited Feb 21 '18 at 07:17

answered Feb 21 '18 at 05:50

void

36,090
8
62
107

If you're aiming for ES6 anyway, just use `function destroyer(a, ...b) {` – Bergi Feb 21 '18 at 05:51
@Bergi correct.. edited! – void Feb 21 '18 at 07:17

Pavan Bahuguni · Accepted Answer · 2018-02-21T05:49:34.560

0

Try this

function destroyer(arr) {
  var args = Array.prototype.slice.call(arguments);
  var a = args[0];
  var b = args.slice(1);

  for (var i=0; i < a.length; i++) {
    if (b.indexOf(a[i]) !== -1) {
      a.splice(i,1);
      i--;
    }
  }
  return a;
}

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

edited Feb 21 '18 at 05:49

answered Feb 21 '18 at 05:48

Pavan Bahuguni

1,947
1
15
21

What did you change and why? – Bergi Feb 21 '18 at 05:49

CodeLover · Answer 3 · 2018-02-21T06:12:13.500

0

This approach with destroyer2() is much simpler and faster with benchmark

function destroyer(arr) {
  var a = Array.prototype.slice.call(arguments);
  var b = a.splice(0,1)[0];
  
  b = b.filter(el => !a.includes(el));
  console.log(b);
}

console.time('destroyer1');
destroyer([1, 2, 3, 1, 2, 3], 2, 3);
console.timeEnd('destroyer1');

// This is much faster than the previous example
function destroyer2(inputs, removables) {
  var len = inputs.length;
  while(len--) {
    if(removables.indexOf(inputs[len]) !== -1) {
      inputs.splice(len, 1); // Remove at specific index if found
    }
  }
  return inputs;
}

console.time('destroyer2');
console.log(destroyer2([1, 2, 3, 1, 2, 3], [2, 3]));
console.timeEnd('destroyer2');

edited Feb 21 '18 at 06:12

answered Feb 21 '18 at 05:53

CodeLover

571
2
11

I can't see how you dare to call `destroyer2` "simpler"… – Bergi Feb 21 '18 at 05:57
It's easy to read and understand – CodeLover Feb 21 '18 at 05:58
Even ignoring the initialisation of `a`, `b` and `c` (which is suboptimal in both functions), those 6 lines of complicated loop code are *not* easier to read and understand than the declarative one-liner – Bergi Feb 21 '18 at 06:01
How do you say its `suboptimal`? What are your basis? – CodeLover Feb 21 '18 at 06:07
Well `function destroyer2(b, c) {` would obviously be much simpler… – Bergi Feb 21 '18 at 06:07
Yes, you are right. Thanks for pointing out. – CodeLover Feb 21 '18 at 06:10

how to remove all elements from the initial array that are of the same value as these arguments?

3 Answers3