Sometimes, we want to pass parameters to a promise function with JavaScript.

In this article, we’ll look at how to pass parameters to a promise function with JavaScript.

How to pass parameters to a promise function with JavaScript?

To pass parameters to a promise function with JavaScript, we can create a function that takes the parameters we want to returns the promise.

For instance, we write

const f = (username, password) => {
  return new Promise((resolve, reject) => {
    //...
    if (success) {
      resolve("Stuff worked!");
    } else {
      reject(Error("It broke"));
    }
  });
}
f('username', 'password')

to create the f function that takes the username and password.

In it, we return a promise created by the Promise constructor.

The callback that we pass into Promise does something with username and password and call resolve if success is true and reject otherwise to reject the promise.

Then we call f with the arguments we want.

Conclusion

To pass parameters to a promise function with JavaScript, we can create a function that takes the parameters we want to returns the promise.