JavaScript Create a New Set
To create a new Set in JavaScript, use Set() constructor. Set() constructor accepts an array of elements, and creates a set from this array. If no argument is passed to Set() constructor, then it returns an empty set.
Syntax
The syntax to create a Set using Set() constructor is
new Set() //empty set new Set([element1, element2, ..., elementN]) //set from array
Examples
In the following example, we create an empty set, and add some elements to it.
index.html
<!DOCTYPE html> <html lang="en"> <body> <pre id="output"></pre> <script> var set1 = new Set(); //create empty set set1.add('apple'); //add element to set set1.add('banana'); //add element to set var displayOutput = ''; set1.forEach (function(element) { displayOutput += element + '\n'; }); document.getElementById('output').innerHTML += displayOutput; </script> </body> </html>
In the following example, we create a set with by passing an array of elements as argument to Set() constructor.
index.html
<!DOCTYPE html> <html lang="en"> <body> <pre id="output"></pre> <script> //create set from array var set1 = new Set(['apple', 'banana', 'cherry']); var output = ''; set1.forEach (function(element) { output += element + '\n'; }); document.getElementById('output').innerHTML += output; </script> </body> </html>
Conclusion
In this JavaScript Tutorial, we learned how to create a Set in JavaScript using Set() constructor, with examples.