JavaScript get Function
Last Updated :
22 Sep, 2023
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" , "Geeksforgeeks" ],
get GFG() {
if ( this .arr.length === 0) return undefined;
return this .arr[ this .arr.length - 1];
}
};
console.log(obj.GFG);
|
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);
|
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);
|
Output
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);
|
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);
|
Output
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);
|
Output
This is a static getter
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