What are the three possible states of a JavaScript Promise object?
Option C is correct. A Promise is an object representing the eventual completion or failure of an asynchronous operation. Its 3 states are: Pending (initial), Fulfilled (success), and Rejected (error).
Which DOM method selects the first element in the document matching a specified CSS selector?
Option A is correct. document.querySelector('selector') returns the first Element within the document that matches the specified CSS selector string.
What is the key storage capacity and lifetime difference between localStorage and sessionStorage in Web Storage API?
Option A is correct. localStorage data has no expiration time and persists until manually deleted. sessionStorage data is cleared automatically when the specific browser window or tab is closed.
What will be the output of console.$\log(1 + '2' + 3)$ in JavaScript?
Option C is correct. Evaluation goes left to right: 1 + '2' coerces 1 to string '1' resulting in '12'. Then '12' + 3 coerces 3 to string '3', producing '123'.
Which ES6 feature provides a concise syntax for defining functions and lexically binds the this value?
Option A is correct. Arrow functions (() => {}) offer shorthand syntax and do not create their own this context-they inherit this lexically from the parent scope.