Slice and Splice without a for loop

JavaScript
1

In answering this question, I proposed this answer:


function frankenSplice(arr1, arr2, n) {
  let arrHold1 = arr1.slice(0,(arr1.length));
  let arrHold2 = arr2.slice();
  arrHold2.splice(n,0,arr1);
  var arr2 = arrHold2;
  return arr2;
}

console.log(frankenSplice([1, 2, 3], [4, 5, 6], 0));

Which as far as I can tell works perfectly. But the tests fail because I didn’t do it in a for loop. The quest never requires a for loop, so why isn’t my answer valid?

browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36.

Link to the challenge:

2

You are not coping the elements of one array into another, you are assigning the reference of the same array to multiple variables.

3

Your answer does not work, you’re splicing in the whole copy of array1 rather than the values from it, so the result of the console log example there is:

[ [ 1, 2, 3 ], 4, 5, 6 ]

Also what @MatteoCarotta said, you’re doing it for both arrays. You copy them fine, but then you overwrite the existing ones instead of sticking with the copies.

4

Ohhhhhh!! lightbulb

Thank you both! I get it now.

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