Checks if a string is lower case.
String.prototype.toLowerCase()
and compare it to the original.const isLowerCase = str => str === str.toLowerCase();
isLowerCase('abc'); // true
isLowerCase('a3@$'); // true
isLowerCase('Ab4'); // false
JavaScript, String
Creates a string with uppercase characters converted to lowercase and vice versa.
JavaScript, String
Checks if a string is an anagram of another string (case-insensitive, ignores spaces, punctuation and special characters).
JavaScript, String
Checks if a string contains a substring, case-insensitive.