JavaScript, be more specific in array comparision

Question

I'm wondering if there is a short way to compare two arrays like:

[1, 2, 3, 4].equals([1, 2, *, 4]) // where * is any value, I want this expression to be true

Or is there a way to be more specific

[1, 2, 3, 4].equals([1, 2, 0 or 2 or 5, 4]) // true

Check this post out: https://stackoverflow.com/questions/7837456/how-to-compare-arrays-in-javascript — doo_doo_fart_man, Jan 12 '21 at 22:26
Does this answer your question? [How to compare arrays in JavaScript?](https://stackoverflow.com/questions/7837456/how-to-compare-arrays-in-javascript) — doo_doo_fart_man, Jan 12 '21 at 22:27
Have you tried anything? There is no built in ways to do it. It is a simple loop with a comparison check — epascarello, Jan 12 '21 at 22:27

Zac Anger · Answer 1 · 2021-01-12T22:44:19.233

const compareArraysExceptIndices = (xs, ys, is = [], alts = []) =>
  xs.reduce((prev, curr, index) => {
    const isMatch = ys[index] === curr
    const isValidAlternative = alts.length
      ? is.includes(index) && alts.includes(ys[index])
      : is.includes(index)
    return prev && (isMatch || isValidAlternative)
  }, true)

console.log(compareArraysExceptIndices([1,2,3], [1,2,3])) // true
console.log(compareArraysExceptIndices([1,2,3], [1,1,3])) // false
console.log(compareArraysExceptIndices([1,2,3], [1,1,3], [1])) // true
console.log(compareArraysExceptIndices([1,2,3], [1,1,3], [1], [1])) // true
console.log(compareArraysExceptIndices([1,2,3], [1,1,3], [1], [2])) // true

This will handle all the cases you're asking about.

score 0 · Answer 2 · answered Jan 12 '21 at 22:33

0

I suppose you intend the * as a wildcard:

const arrCmp = (arr1, arr2) => {
  const len = arr1.length;

  for (let i = 0; i < len; i++) {
    if (arr1[i] !== arr2[i] && arr1[i] !== "*" && arr2[i] !== "*") return false;
  }

  return true;
};

answered Jan 12 '21 at 22:33

domenikk

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JavaScript, be more specific in array comparision

2 Answers2