JavaScript set has() method is used to check whether the Set object contains the specified value or not. This method returns a boolean indicating whether an element with the specified value exists in a Set object or not.
setObj.has(value)
JavaScript has() method
Simple example code.
<!DOCTYPE html>
<html>
<body>
<script>
const set1 = new Set([1, 2, 3, 4, 5]);
console.log(set1.has(1));
console.log(set1.has(5));
console.log(set1.has(6));
</script>
</body>
</html>Output:
Checking if a Set contains a list in JavaScript
var a = new Set();
var b = [1];
a.add(b);
a.has(b); // => trueMore example
const mySet = new Set();
mySet.add('foo');
mySet.has('foo'); // returns true
mySet.has('bar'); // returns false
const set1 = new Set();
const obj1 = {'key1': 1};
set1.add(obj1);
set1.has(obj1); // returns true
set1.has({'key1': 1}); // returns false because they are different object references
set1.add({'key1': 1}); // now set1 contains 2 entriesDo comment if you have any doubts or suggestions on this Js set method topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version