then < Promise < JavaScript

The then() method of a Promise object takes up to two arguments: callback functions for the fulfilled and rejected cases of the Promise. It immediately returns an equivalent Promise object, allowing you to chain calls to other promise methods.

    
    const promise1 = new Promise((resolve, reject) => {
      resolve('Success!');
    });

    promise1.then((value) => {
      console.log(value);
    });
    // "Success!"