The JavaScript WeakMap has() method to find out if the WeakMap object contains the specified value element.
Syntax:
WeakMapObj.has(key)
WeakMapObj.has(key)
WeakMapObj.has(key)
Parameters:
key: It represents the key to be found in the WeakMap object.
Returns:
It returns true if the given key is present in the WeakMap, otherwise returns false.
Example 1:
<!DOCTYPE html>
<html>
<body>
<script>
var hello = new WeakMap();
var obj = {};
hello.set(obj, 'HELLO');
document.writeln(hello.has(obj));
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<script>
var hello = new WeakMap();
var obj = {};
hello.set(obj, 'HELLO');
document.writeln(hello.has(obj));
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<script>
var hello = new WeakMap();
var obj = {};
hello.set(obj, 'HELLO');
document.writeln(hello.has(obj));
</script>
</body>
</html>
Example 2:
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
const testWeakmap = new WeakMap();
const object1 = {};
const object2 = {};
testWeakmap.set(object1, 'w3schools');
document.write(testWeakmap.has(object1));
document.write("</br>");
document.write(testWeakmap.has(object2));
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
const testWeakmap = new WeakMap();
const object1 = {};
const object2 = {};
testWeakmap.set(object1, 'w3schools');
document.write(testWeakmap.has(object1));
document.write("</br>");
document.write(testWeakmap.has(object2));
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
const testWeakmap = new WeakMap();
const object1 = {};
const object2 = {};
testWeakmap.set(object1, 'w3schools');
document.write(testWeakmap.has(object1));
document.write("</br>");
document.write(testWeakmap.has(object2));
</script>
</body>
</html>