method-chaining

method chaining = calling one method after another in one continuous line of code, it makes your code cleaner and more readable

code without method chaining


let userName = "jack12";
let letter = userName.charAt(0);
letter = letter.toUpperCase();

console.log(letter);

same code with method chaining takes less space


let username = "jack12";
let letter = username.charAt(0).toUpperCase();

console.log(letter);