Method chaining

method chaining ⇒ calling on method after another in one continuous line of code

No method chaining

let username = window.prompt("enter your username")
 
username = username.trim();
let letter = username.charAt(0);
letter = letter.toUpperCase();
 
let extraChars = username.slice(1);
extraChars = extraChars.toLowerCase();
username = letter + extraChars;
 
console.log(username);

Method chaining

username = username.trim().charAt(0).toUpperCase() + username.trim().slice(1).toLowerCase();
 
console.log(username)