Check if two strings are anagram

const areAnagram = (str1, str2) =>
    str1.toLowerCase().split('').sort().join('') === str2.toLowerCase().split('').sort().join('');

const areAnagram = (str1: string, str2: string): boolean =>
    str1.toLowerCase().split('').sort().join('') === str2.toLowerCase().split('').sort().join('');

areAnagram('listen', 'silent'); // true
areAnagram('they see', 'the eyes'); // true
areAnagram('node', 'deno'); // true