how to get lowercase with first letter captal in js code example

Example 1: javascript capitalize first letter

const lower = 'this is an entirely lowercase string';
const upper = lower.charAt(0).toUpperCase() + lower.substring(1);

Example 2: javascript string first letter lowercase

// for lowercase on first letter
let s = "This is my string"
let lowerCaseFirst = s.charAt(0).toLowerCase() + s.slice(1)