make first letter of string lowercase javascript code example

Example 1: javascript lowercase string

var str = "My Big Boy!"
var res = str.toLowerCase(); //res is "my big boy!"

Example 2: how to convert whole strig in lowercase in js

var str = "Hello World!";
var res = str.toLowerCase();

Example 3: 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)