Jun 27, 2021 · Object.keys, values, entries. For plain objects, the following methods are available: Object.keys(obj) – returns an array of keys. Object.values(obj) – returns an array of values. Object.entries(obj) – returns an array of [key, value] pairs. Please note the distinctions (compared to map for example):

The Object.keys() method returns an array with the keys of an object. The Object.keys() method does not change the original object.

Object.keys() The Object.keys() method returns an array of a given object's own enumerable properties, 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). var arr1 = Object.keys(obj);

You should either iterate with for..in, or Object.keys, like this. for (var key in dictionary) { // check if the property/key is defined in the object itself, not in parent if (dictionary.hasOwnProperty(key)) { console.log(key, dictionary[key]); } }

Apr 28, 2025 · Object.keys() returns an array whose elements are strings corresponding to the enumerable string-keyed property names found directly upon object. This is the same as iterating with a for...in loop, except that a for...in loop enumerates properties in the prototype chain as well.

Jan 14, 2020 · There are two ways to add new properties to an object: key1: value1, key2: value2. The first form is used when you know the name of the property. The second form is used when the name of the property is dynamically determined. Like in this example: return obj[propertyName]; A real JavaScript array can be constructed using either: obj is an object.

Nov 11, 2020 · Let’s start by creating an object. I'll create an object called pizza below, and add key-value pairs to it. The keys are to the left of the colon : and the values are to the right of it. Each key-value pair is a property. There are three properties in this example: The key topping has a value “cheese”. The key sauce has a value “marinara”.

Aug 11, 2020 · The keys, values, and entries are 3 common lists to extract from a JavaScript object for further processing. JavaScript provides the necessary utility function to access these lists: The keys are returned by Object.keys(object)

Nov 22, 2022 · In JavaScript, there are three methods that can be used to manipulate objects: Object.keys (), Object.values (), and Object.entries (). These methods allow developers to easily access and...

Mastering JavaScript object manipulation techniques, including Object.keys, Object.values, Object.entries, and Object.fromEntries, is pivotal for any aspiring JavaScript developer. These methods offer robust solutions for accessing, transforming, and iterating over object properties, significantly enhancing your ability to manage and manipulate ...