Q135- What is a promise? Can you write a simple promise that resolves after 1 second

A Promise is an object that represents the eventual completion (or failure) of an asynchronous operation and its resulting value.

It has three states:

1. Pending → initial state, not resolved or rejected.
2. Fulfilled → operation completed successfully.
3. Rejected → operation failed.

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⚡ Simple Promise Example (Resolves after 1 second)

const waitOneSecond = new Promise((resolve, reject) => {
  setTimeout(() => {
    resolve("Done after 1 second");
  }, 1000);
});

waitOneSecond.then((message) => {
  console.log(message);
});

Output (after 1 second):

Done after 1 second

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💡 Explanation:

• new Promise() takes a function with resolve and reject.
• resolve() → marks the promise as fulfilled.
• reject() → marks it as failed.
• .then() is used to handle the fulfilled value.
• .catch() can handle errors if rejected.

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✅ In Short:

A Promise is a way to handle async operations in JavaScript without getting into “callback hell.”

Example usage: API calls, timers, or any async tasks.