JavaScript: Promise

A Promise in JavaScript is an object that represents the eventual completion (or failure) of an asynchronous operation and its resulting value. It has three states: pending, fulfilled, and rejected.

Here, a boolean variable controls whether the Promise resolves or rejects.

A function returns a Promise, which resolves or rejects based on the parameter value.

.then() handles resolved results, and .catch() handles rejections.

Use console.log() before the asynchronous task to simulate a real-world fetch operation.

Combining .then() and .catch() directly improves code readability.

This Promise wraps a jQuery AJAX call to simulate real-world API usage.