tolowercase javascript

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

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

const sentence = 'The quick brown fox jumps over the lazy dog.';

console.log(sentence.toLowerCase());
// expected output: "the quick brown fox jumps over the lazy dog."

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

str.toLowerCase()

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