Intermediate Algorithm Scripting: Seek and Destroy_Help Please

JavaScript
1

I wondered if I could get some help with my code. I don’t understand why my variable ‘output’ is logging the following to the console:

1

1,2

1,2,3

1,2,3,1

1,2,3,1,2

1,2,3,1,2,3

Here is my code in full:

function destroyer(arr) {
  // Remove all the values
  let args = Array.prototype.slice.call(arguments);
  let newArr = args[0];
  let newArgs = args.slice(1);
  let output = [];
  for (let i = 0; i < newArr.length; i++) {
    if (newArgs.indexOf(newArr[i] === -1)){
      output.push(newArr[i]);
      console.log(output);
    }
  }
  return output;
}

destroyer([1, 2, 3, 1, 2, 3], 2, 3);
2 
(newArgs.indexOf(newArr[i] === -1))

Look at where your parentheses begin and end. Is it doing what you want it to?

3

if (newArgs.indexOf(newArr[i] === -1)){

should be

if (newArgs.indexOf(newArr[i]) === -1){

4

Thanks so much! I completely missed that.

5

Let’s see this line, from inside out.

newArr[i] === -1 is false
newArgs.indexOf(false) is -1
And as -1 is truthy, the code inside the if statement is always executed, resulting in all the elements in newArr being pushed to output

Can you figure out how to fix this?