Javascript Promises in Simple Term

JavaScript Promises are a language feature that allows you to work with asynchronous code in a more synchronous way. They provide a way to handle asynchronous results in a more sequential, easier-to-read manner.

Promises are a pattern that you can use to structure your code to handle asynchronous tasks in a way that is easier to understand and maintain. They consist of a function that returns a Promise object, which represents the eventual completion (or failure) of an asynchronous operation, and a set of methods for working with the Promise.

Here's an example of how you might use a Promise to handle an asynchronous operation:

function getData() {
  return new Promise(function(resolve, reject) {
    // Do an async task (such as making an HTTP request)
    if (/* async task is successful */) {
      resolve(/* async result */);
    } else {
      reject(/* error */);
    }
  });
}

getData().then(function(result) {
  // do something with the result
}).catch(function(error) {
  // handle the error
});

In this example, the getData() function returns a Promise that represents the completion of an asynchronous operation. When the operation completes successfully, the Promise's resolve() function is called with the async result. If the operation fails, the Promise's reject() function is called with an error. The then() and catch() methods of the Promise allow you to specify callback functions that will be called when the Promise is resolved or rejected, respectively.

Promises are a useful way to structure your code and make it easier to read and maintain. They can also help you avoid callback hell, which is a common problem when working with asynchronous code.