How to Convert a String to Lowercase and Uppercase in JS

JavaScript String toLowerCase() Method - W3Schools

The toLowerCase() method converts a string to lowercase letters. The toLowerCase() method does not change the original string.

This article explains how to convert a string to lowercase and uppercase characters. We'll also go over how to make only the first letter in a word uppercase.

Convert JavaScript String to be all lowercase - Stack Overflow

E.g., "and" to "AND". Converting to uppercase: Example code: