Checks if a string is upper case.
String.prototype.toUpperCase()
and compare it to the original.const isUpperCase = str => str === str.toUpperCase();
isUpperCase('ABC'); // true
isUpperCase('A3@$'); // true
isUpperCase('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.