We can also add a property by using the bracket notation as follows: obj ['foo'] = 1; Sometimes we want to add dynamic properties to an object in JavaScript. Dot syntax is simpler and is generally sufficient. Adding New Properties. To add a new property to an object, specify the object name followed by: a dot, the name of the new property, an equals sign, and the value for the new property (enclosed in quotes if it is a string). Javascript add property to Object. by Kaashan Hussain We all deal with objects in one way or another while writing code in a programming language. We use cookies to ensure you have the best browsing experience on our website. For instance, we expect to get Properties names from a user inputting. 'A new string value for our original string property' 1. Properties on the Javascript object help set values that can be used within the object to manage and use the data. In this post, we will see how to add a property to an object in JavaScript.A simple approach is to use the dot notation with assignment operator to add a property to an existing object. To add a new property to an object, specify the object name followed by: a dot, the name of the new property, an equals sign, and the value for the new property (enclosed in quotes if it is a string).
acknowledge that you have read and understood our By profession, he is a web developer with knowledge of multiple back-end platforms (e.g., PHP, Node.js, Python) and frontend JavaScript frameworks (e.g., Angular, React, and Vue). When using dot syntax, the value after the dot needs to be a valid identifier,Square bracket syntax is necessary if a property name contains spaces or other special characters, or if it consists of a keyword reserved in JavaScript. © 2017-2020 Sprint Chase Technologies. The syntax is: All above methods overwrites the source object with properties of the given object if they have any key in common, except the Enter your email address to subscribe to new posts and receive notifications of new posts by email. Otherwise, JavaScript errors will be your result.To change a value of the existing property of an object, specify the object name followed by a square bracket, the name of the property you wish to change, an equals sign, and the new value you want to assign. To add a new property to Javascript object, define the object name followed by the dot, the name of a new property, an equals sign and the value for the new property. I will try to cover that in a another topic. The process for modifying a property is essentially the same. A simple approach is to use the dot notation with assignment operator to add a property to an existing object. Example. Modify a Property of an Object Literal. This article has covered JavaScript object prototypes, including how prototype object chains allow objects to inherit features from one another, the prototype property and how it can be used to add methods to constructors, and other related topics. The second form is used when the name of the property is dynamically determined.
We can add the property to JavaScript object using a variable as the name by using dot notation or bracket notation.Below example illustrate explain two different approaches:If you like GeeksforGeeks and would like to contribute, you can also write an article using Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.Please write to us at contribute@geeksforgeeks.org to report any issue with the above content. All rights reservedIs it possible to add properties to this Object after its initial creation if the properties’ name is not determined until run time? There’re a few ways to add properties to an object in JavaScript. There are many ways in which objects in JavaScript differ from objects in other mainstream programming languages, like Java.