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    Promise.resolve()

    The Promise.resolve(value) method returns a Promise object that is resolved with the given value. If the value is a thenable (i.e. has a then method), the returned promise will "follow" that thenable, adopting its eventual state; otherwise the returned promise will be fulfilled with the value.

    Syntax

    Promise.resolve(value);
Promise.resolve(promise);
Promise.resolve(thenable);

    Parameters

    value
    Argument to be resolved by this Promise. Can also be a Promise or a thenable to resolve.

    Description

    The static Promise.resolve function returns a Promise that is resolved.

    Examples

    Using the static Promise.resolve method

    Promise.resolve("Success").then(function(value) {
  console.log(value); // "Success"
}, function(value) {
  // not called
});

    Resolving an array

    var p = Promise.resolve([1,2,3]);
p.then(function(v) {
  console.log(v[0]); // 1
});

    Resolving another Promise

    var original = Promise.resolve(true);
var cast = Promise.resolve(original);
cast.then(function(v) {
  console.log(v); // true
});

    Resolving thenables and throwing Errors

    // Resolving a thenable object
var p1 = Promise.resolve({ 
  then: function(onFulfill, onReject) { onFulfill("fulfilled!"); }
});
console.log(p1 instanceof Promise) // true, object casted to a Promise

p1.then(function(v) {
    console.log(v); // "fulfilled!"
  }, function(e) {
    // not called
});

// Thenable throws before callback
// Promise rejects
var thenable = { then: function(resolve) {
  throw new TypeError("Throwing");
  resolve("Resolving");
}};

var p2 = Promise.resolve(thenable);
p2.then(function(v) {
  // not called
}, function(e) {
  console.log(e); // TypeError: Throwing
});

// Thenable throws after callback
// Promise resolves
var thenable = { then: function(resolve) {
  resolve("Resolving");
  throw new TypeError("Throwing");
}};

var p3 = Promise.resolve(thenable);
p3.then(function(v) {
  console.log(v); // "Resolving"
}, function(e) {
  // not called
});

    Specifications

    Specification Status Comment
    ECMAScript 2015 (6th Edition, ECMA-262)
    The definition of 'Promise.resolve' in that specification.    		 Standard Initial definition in an ECMA standard.
    ECMAScript 2017 Draft (ECMA-262)
    The definition of 'Promise.resolve' in that specification.    		 Draft  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
    Basic support 32 [1] 29.0 (29.0) No support 19 7.1
    Feature Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile Chrome for Android
    Basic support No support 29.0 (29.0) No support No support 8 32

    [1] Chrome/v8 also supports a non-standard method Promise.accept(). However, it is recommended to use this standard Promise.resolve() method instead as the accept method is going to be removed in the future (issue 3238).

    See also

    Document Tags and Contributors

    Tags: 
     Contributors to this page: fscholz, realityking
     Last updated by: fscholz,