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Q:

js create a promise

/*
	A Promise is a proxy for a value not necessarily known when the promise is created. 
    It allows you to associate handlers with an asynchronous action's eventual success 
    value or failure reason.
*/            
let promise = new Promise((resolve , reject) => {
  fetch("https://myAPI")
    .then((res) => {
      // successfully got data
      resolve(res);
    })
    .catch((err) => {
      // an error occured
      reject(err);
    });          
});
5
var promise = new Promise(function(resolve, reject) {
  // do some long running async thing…
  
  if (/* everything turned out fine */) {
    resolve("Stuff worked!");
  }
  else {
    reject(Error("It broke"));
  }
});

//usage
promise.then(
  function(result) { /* handle a successful result */ },
  function(error) { /* handle an error */ }
);
29
let myFirstPromise = new Promise((resolve, reject) => {
  // We call resolve(...) when what we were doing asynchronously was successful, and reject(...) when it failed.
  // In this example, we use setTimeout(...) to simulate async code. 
  // In reality, you will probably be using something like XHR or an HTML5 API.
  setTimeout( function() {
    resolve("Success!")  // Yay! Everything went well!
  }, 250) 
}) 

myFirstPromise.then((successMessage) => {
  // successMessage is whatever we passed in the resolve(...) function above.
  // It doesn't have to be a string, but if it is only a succeed message, it probably will be.
  console.log("Yay! " + successMessage) 
});

2
getData()
    .then(data => console.log(data))
    .catch(error => console.log(error));
1
function getData() {
    return new Promise((resolve, reject)=>{
        request( `http://www.omdbapi.com/?t=The+Matrix`, (error, res, movieData)=>{
            if (error) reject(error);
            else resolve(movieData);
        });
    });
}
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