tolowercase javascript

var str = "My Big Boy!"
var res = str.toLowerCase(); //res is "my big boy!"var str = "Hello World!";
var res = str.toLowerCase();var str = "ExaMple";
var res = str.toLowerCase();
output res -> "example"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."
str.toLowerCase()