iterate over object keys js code example

Example 1: iterate key value object javascript

'use strict';
// ECMAScript 2017
const object = {'a': 1, 'b': 2, 'c' : 3};
for (const [key, value] of Object.entries(object)) {
  console.log(key, value);
}

Example 2: javascript loop through object

// object to loop through
let obj = { first: "John", last: "Doe" };

// loop through object and log each key and value pair
//ECMAScript 5
Object.keys(obj).forEach(function(key) {
    console.log(key, obj[key]);
});

//ECMAScript 6
for (const key of Object.keys(obj)) {
    console.log(key, obj[key]);
}

//ECMAScript 8
Object.entries(obj).forEach(
    ([key, value]) => console.log(key, value)
);

// OUTPUT
/*
   first John
   last Doe
*/

Example 3: loop over keys in object javascript

Object.keys(obj).forEach(function(key) {
  console.log(key, obj[key]);
});

Example 4: javascript iterate over object keys and values

const object1 = {
  a: 'somestring',
  b: 42
};

for (let [key, value] of Object.entries(object1)) {
  console.log(`${key}: ${value}`);
}

// expected output:
// "a: somestring"
// "b: 42"
// order is not guaranteed

Example 5: javascript loop through object

var person = {"name":"bob", age:45};

for (var property in person) {
   console.log(person[property]);
}