The Object.entries() method returns an array of a given object's own enumerable property [key, value] pairs, in the same order as that provided by a for...in loop (the difference being that a for-in loop enumerates properties in the prototype chain as well).
Syntax
Object.entries(obj)
Parameters
obj- The object whose enumerable own property
[key, value]pairs are to be returned.
Return value
An array of the given object's own enumerable property [key, value] pairs.
Description
Object.entries() returns an array whose elements are arrays corresponding to the enumerable property [key, value] pairs found directly upon object. The ordering of the properties is the same as that given by looping over the property values of the object manually.
Examples
var obj = { foo: 'bar', baz: 42 };
console.log(Object.entries(obj)); // [ ['foo', 'bar'], ['baz', 42] ]
// array like object
var obj = { 0: 'a', 1: 'b', 2: 'c' };
console.log(Object.entries(obj)); // [ ['0', 'a'], ['1', 'b'], ['2', 'c'] ]
// array like object with random key ordering
var an_obj = { 100: 'a', 2: 'b', 7: 'c' };
console.log(Object.entries(an_obj)); // [ ['2', 'b'], ['7', 'c'], ['100', 'a'] ]
// getFoo is property which isn't enumerable
var my_obj = Object.create({}, { getFoo: { value: function() { return this.foo; } } });
my_obj.foo = 'bar';
console.log(Object.entries(my_obj)); // [ ['foo', 'bar'] ]
// non-object argument will be coerced to an object
console.log(Object.entries('foo')); // [ ['0', 'f'], ['1', 'o'], ['2', 'o'] ]
// iterate through key-value gracefully
var obj = {a: 5, b: 7, c: 9};
for (var [key, value] of Object.entries(obj)) {
console.log(key + ' ' + value); // "a 5", "b 7", "c 9"
}
// Or, using array extras
Object.entries(obj).forEach(([key, value]) => {
console.log(key + ' ' + value); // "a 5", "b 7", "c 9"
});
Converting an Object to a Map
The new Map() constructor accepts an iterable of entries. With Object.entries, you can easily convert from Object to Map:
var obj = { foo: 'bar', baz: 42 };
var map = new Map(Object.entries(obj));
console.log(map); // Map { foo: "bar", baz: 42 }
Polyfill
To add compatible Object.entries support in older environments that do not natively support it, you can find a Polyfill in the tc39/proposal-object-values-entries or in the es-shims/Object.entries repositories.
Specifications
| Specification | Status | Comment |
|---|---|---|
| ECMAScript Latest Draft (ECMA-262) The definition of 'Object.entries' in that specification. |
Living Standard | Initial definition. |
| ECMAScript 2017 (ECMA-262) The definition of 'Object.entries' in that specification. |
Standard |
Browser compatibility
| Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|---|
| Basic support | 54 | (Yes) | 47 (47) | No support | No support | 10.1 |
| Feature | Android Webview | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Basic support | 54 | 54 | (Yes) | 47.0 (47) | No support | No support | No support |