[javascript] Iterate over values of object

I want to iterate over all values of a map. I know it's possible to iterate over all keys. But is it possible to iterate directly over the values?

 var map = { key1 : 'value1', key2 : 'value2' }
 for (var key in map) { ...} // iterates over keys

This question is related to javascript dictionary

The answer is


In case you want to deeply iterate into a complex (nested) object for each key & value, you can do so using Object.keys():

const iterate = (obj) => {
    Object.keys(obj).forEach(key => {

    console.log(`key: ${key}, value: ${obj[key]}`)

    if (typeof obj[key] === 'object') {
            iterate(obj[key])
        }
    })
}

I iterate like this and it works for me.

for (let [k, v] of myMap) {
    console.log("Key: " + k);
    console.log("Value: " + v);
}

Hope this helps :)


EcmaScript 2017 introduced Object.entries that allows you to iterate over values and keys. Documentation

var map = { key1 : 'value1', key2 : 'value2' }

for (let [key, value] of Object.entries(map)) {
    console.log(`${key}: ${value}`);
}

The result will be:

key1: value1
key2: value2


You could use underscore.js and the each function:

_.each({key1: "value1", key2: "value2"}, function(value) {
  console.log(value);
});

No, there's no direct method to do that with objects.

The Map type does have a values() method that returns an iterator for the values


In the sense I think you intended, in ES5 or ES2015, no, not without some work on your part.

In ES2016, probably with object.values.

Mind you Arrays in JavaScript are effectively a map from an integer to a value, and the values in JavaScript arrays can be enumerated directly.

['foo', 'bar'].forEach(v => console.log(v)); // foo bar

Also, in ES2015, you can make an object iterable by placing a function on a property with the name of Symbol.iterator:

var obj = { 
    foo: '1', 
    bar: '2',
    bam: '3',
    bat: '4',
};

obj[Symbol.iterator] = iter.bind(null, obj);

function* iter(o) {
    var keys = Object.keys(o);
    for (var i=0; i<keys.length; i++) {
        yield o[keys[i]];
    }
}

for(var v of obj) { console.log(v); } // '1', '2', '3', '4'

Also, per other answers, there are other built-ins that provide the functionality you want, like Map (but not WeakMap because it is not iterable) and Set for example (but these are not present in all browsers yet).