Set.prototype.has()
The has() method of Set instances returns a boolean indicating whether an
element with the specified value exists in this set or not.
Try it
Syntax
js
has(value)
Parameters
value-
The value to test for presence in the
Setobject.
Return value
Returns true if an element with the specified value exists in the Set object; otherwise false.
Examples
Using the has() method
js
const mySet = new Set();
mySet.add("foo");
console.log(mySet.has("foo")); // true
console.log(mySet.has("bar")); // false
const set1 = new Set();
const obj1 = { key1: 1 };
set1.add(obj1);
console.log(set1.has(obj1)); // true
console.log(set1.has({ key1: 1 })); // false, because they are different object references
console.log(set1.add({ key1: 1 })); // now set1 contains 2 entries
Specifications
| Specification |
|---|
| ECMAScript Language Specification # sec-set.prototype.has |
Browser compatibility
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