function isAnagram(a, b) {
  const norm = (s) =>
    s.toLowerCase().replace(/\s/g, "").split("").sort().join("");
  return norm(a) === norm(b);
}
isAnagram("Dormitory", "Dirty Room"); // true

Normalise-then-sort is O(n log n) and readable. For O(n), count character frequencies into an object and compare those.

sandbox.js

function isAnagram(a, b) {
  // TODO
}

Output

Hit “Run tests” to check your solution.

All problems

Next question

JavaScriptMedium13/15

Write isAnagram(a, b) checking whether two strings are anagrams (ignoring case and spaces)

By FrontendPro Editorial Team Updated 8/7/2026

Explore the JavaScript interview guide

Examples

Write isAnagram so that the following cases hold.

InputisAnagram("listen", "silent")
Outputtrue
InputisAnagram("Dormitory", "Dirty Room")
Outputtrue
InputisAnagram("hello", "world")
Outputfalse

1 more hidden test cases - 4 in total will be graded.

Answer

function isAnagram(a, b) {
  const norm = (s) =>
    s.toLowerCase().replace(/\s/g, "").split("").sort().join("");
  return norm(a) === norm(b);
}
isAnagram("Dormitory", "Dirty Room"); // true