JavaScript sets Object is a collection of unique values. It stores unique values of any type, whether primitive values or object references.
To create a new empty Set use the following syntax:
let setObject = new Set();Optional you can pass an iterable object to the Set constructor, all the elements of the iterable object will be added to the new set:
let setObject = new Set(iterableObject);JavaScript sets
Simple example code creates a new Set from an Array.
<!DOCTYPE html>
<html>
<body>
<script>
var arr = ['a', 'a', 'b', 'c', 'c'];
let chars = new Set(arr);
console.log(chars)
console.log(typeof(chars))
</script>
</body>
</html>
Output: All elements in the set must be unique therefore it chars only contains 3 distinct elements a, b and c.
Looping the elements of a JavaScript Set
// Create a Set
const letters = new Set(["a","b","c"]);
// List all entries
let text = "";
letters.forEach (function(value) {
text += value;
})Set Methods
| Methods | Description |
|---|---|
| add() | It adds the specified values to the Set object. |
| clear() | It removes all the elements from the Set object. |
| delete() | It deletes the specified element from the Set object. |
| entries() | It returns an object of Set iterator that contains an array of [value, value] for each element. |
| forEach() | It executes the specified function once for each value. |
| has() | It indicates whether the Set object contains the specified value element. |
| values() | It returns an object of Set iterator that contains the values for each element. |
Do comment if you have any doubts or suggestions on this JS code.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version