JavaScript Set() Constructor Last Updated : 12 Jul, 2024 Comments Improve Suggest changes Like Article Like Report The Javascript Set constructor is used to create Set objects. It will create a set of unique values of any type, whether primitive values or object preferences. It returns the new Set object. It mainly helps in creating a new set of objects which contains unique elements.Syntax:new Set()new Set(iterable)Parameters:This method accepts a single parameter that is described below:iterable: If an object is passed, all values will be added to the new set. If the parameter is not specified then the new set is empty.Return Value:This method returns a new Set object.Example 1: In this example, we will see how to create a new Set object. JavaScript const mySet = new Set(); mySet.add("California"); mySet.add("India"); mySet.add("Russia"); mySet.add(10); const myObject = { a: 1, b: 8 }; mySet.add(myObject); console.log(mySet); Output:Set(5) { 'California', 'India', 'Russia', 10, { a: 1, b: 8 } }Example 2: In this example, we will see that set takes only a unique value. JavaScript const mySet = new Set(); mySet.add("California"); mySet.add("India"); mySet.add("California"); mySet.add(10); mySet.add(10); const myObject = { a: 1, a: 5 }; mySet.add(myObject); console.log(mySet); Output:Set(4) { 'California', 'India', 10, { a: 5 } }In this example, we have added two times "California" and 10 but it creates a set with unique values.We have a complete list of Javascript Set methods, to check those please go through this Sets in JavaScript article.Supported Browsers:Chrome Edge Firefox Opera Safari Comment More infoAdvertise with us Next Article JavaScript Set size Property M mansigeekso9ii Follow Improve Article Tags : JavaScript Web Technologies JavaScript-Methods JavaScript-Set Similar Reads JavaScript Set() Constructor The Javascript Set constructor is used to create Set objects. It will create a set of unique values of any type, whether primitive values or object preferences. It returns the new Set object. It mainly helps in creating a new set of objects which contains unique elements.Syntax:new Set()new Set(iter 2 min read JavaScript Set size Property The Set.size property in JavaScript returns the number of elements in a Set. In other words, we can say that this property is used to get the current size of the set. If the Set is empty the size of the set will be returned as 0.Syntax:mySet.sizeReturn Type:Number of elements in the setExample 1: In 2 min read JavaScript Set constructor Property JavaScript Set Constructor Property is used to return the Set constructor() for the object. It only returns the reference of the function and does not return the name of the function. In JavaScript set, it returns the function Set(){ [native code] }. Syntax Set.constructorParameter: It does not take 1 min read JavaScript Set add() Method The Set.add() method in JavaScript is used to append an element with a specified value in a set. It modifies the existing set by appending the new element but does not return a new set. The Set.add() method does not modify the set if the element with a specified value already exists in the set.Synta 3 min read JavaScript Set clear() Method The Set clear() method in JavaScript is used for the removal of all the elements from a set and making it empty. Syntax:mySet.clear();Parameters:This method does not accept any parameters.Return Value:Returns an undefined value.Example 1: Emptying set using Set clear() methodJavaScript// Create a ne 3 min read JavaScript Set delete() Method The delete() method in JavaScript Set deletes an element from the set and returns true if the element existed and was successfully deleted. Otherwise, it returns false if the element does not exist.Syntax:mySet.delete(value);Parameters:value: It is the value of the element that is to be deleted from 3 min read JavaScript Set entries() Method The Set.entries() method returns a new Iterator object that contains an array of [value, value] for each element in the Set object, in the order of their insertion. Although a Set does not contain key-value pairs, to keep similarities with the map.entries() method, it will return key-value pairs whe 2 min read JavaScript Set forEach() Method The set.forEach() method is used to execute the function which is taken as a parameter and applied for each value in the set, in insertion order.Syntax:forEach(function(value, key, set) { /* ... */ }, thisArg)Parameters:Callback function: The function will be executed for each value and it takes thr 3 min read JavaScript Set has() Method The Set.has() method in JavaScript is used to check whether an element with a specified value exists in a Set or not. It returns a boolean value indicating the presence or absence of an element with a specified value in a Set.Syntax:mySet.has(value);Parameters:value: It is the value of the element t 2 min read JavaScript Set values() Method The Set.values() method in JavaScript returns a new Iterator object that contains all of the items available in the set in a certain order. The order of values are in the same order that they were inserted into the set.Syntax:mySet.values()Parameters:This method does not accept any parameters.Return 2 min read Like