Simple JavaScript code in promises.

function promiseExample(){
    const promise = new Promise((resolve, reject) =>{
            resolve('successfully!');
    })
    .then((resolve) => console.log(resolve))
    .catch((reject) => console.log(reject));
  return promise;
}
promiseExample()

I have a create simple code example for promises. you can easily check. how to resolve is working? and how to reject is working?