what’s the shortest anagram detector you know how to write, in javascript?

there must be a shorter way to do this. highlight below to see a solution.

var anagramDetector = function (x,y) {
   if (x.length != y.length) return false;
   var alpha_x = x.split("").sort().join("");
   var alpha_y = y.split("").sort().join("");
   for ( j = 0; j<y.length;++j) {
       if (alpha_x[j] != alpha_y[j]) return false;
  }
  return true;
}

PS: there’s a cool method for solving this for a fixed alphabet, using primes

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