JavaScript get function is used to access the properties of an object using dot notation or square brackets. It allows you to retrieve the value associated with a particular property key and the get function is often used when working with objects that implement JavaScript’s getter function.
The get syntax mainly binds an object property to a function.
Syntax:
{ get prop() { /* … */ } }
{ get [expression]() { /* … */ } }
Parameters:
- prop: Property name to which we bind the given function.
- expression: We can also use the expression in place of the property name to bind the given function.
Return Value: The get function() returns the value associated with the specified propertyName in the objectName. If the property does not exist. It will return undefined.
Define Getter on New Objects in Object Initializers
Define a getter function directly in an object initializer using get keyword followed by property name.
Example: In this example, we will create pseudo-property GFG() which will return
Javascript
const obj = { arr: ["Geeks", "Geeksforneveropen"], get GFG() { if (this.arr.length === 0) return undefined; return this.arr[this.arr.length - 1]; } }; console.log(obj.GFG); |
Geeksforneveropen
Using Getters in Classes
You can define getters within the classes to access computed properties or provide encapsulated access to private variables.
Example:
Javascript
class GFG { constructor() { this._count = 1; } get count() { return this._count; } } const obj = new GFG(); console.log(obj.count); |
1
Deleting a Getter using the delete Operator
You can remove a getter from an object using delete operator.
Example:
Javascript
const obj = { get GFG() { return "This is a getter Function"; } }; console.log(obj.GFG); delete obj.GFG; console.log(obj.GFG); |
This is a getter Function undefined
Defining a Getter on Existing Objects using defineProperty
You can add a getter to an existing object using the Object.defineProperty.
Example:
Javascript
const obj = {}; Object.defineProperty(obj, "GFG", { get: function () { return "Dynamic getter"; } }); console.log(obj.GFG); |
Dynamic getter
Using a Computed Property Name
You can define a getter with a computed property name allowing dynamic property access.
Example:
Javascript
const prop = "GFG"; const obj = { get [prop]() { return "This is computed property name "; } }; console.log(obj.GFG); |
This is computed property name
Defining Static Getter
Static getters are associated with the class rather than instances and can be accessed directly on the class.
Example:
Javascript
class GFG { static get Property() { return "This is a static getter"; } } console.log(GFG.Property); |
This is a static getter
