In this article, we learn how to declare an object with a computed property name. Before beginning this article, we have to know about the javascript objects.
Computed Property Names: The ES6 computed property names feature allows us to compute an expression as a property name on an object.
Javascript Object: Javascript objects contain key-value pairs in which the key represents a property from which we can get and set the value of the object. Now we will see how to declare an object with a computed property name.
Method 1: We will use the expression within the [ ] (square bracket) to create the name of an object property. In ES6, it is possible to use an expression within brackets ‘[ ]’. Depending on the result of the expression, a property name will be assigned to an object.
Example: This example shows the use of the above-explained approach.
let LAST_NAME = "lastname";
let fullname = { firstname: "somya",
[LAST_NAME]: "jain"
};console.log( "My fullname is: " + fullname.firstname
+ " " + fullname.lastname
); |
Output:
My fullname is: somya jain
Method 2: In this method, We will create the property name of an object dynamically. As part of this method, we will dynamically create an object and add a property name and assign a value to that specific property in order to create a customized key-value pair.
Syntax:
objectname["name of the property name"]=value
Example: This example shows the use of the above-explained approach.
let LAST_NAME = "lastname";
let fullname = { firstname: "somya"
};fullname[LAST_NAME] = "jain";
console.log( "My fullname is: " + fullname.firstname
+ " " + fullname.lastname
); |
Output:
My fullname is: somya jain