The JavaScript WeakMap has() method to find out if the WeakMap object contains the specified value element.
Syntax:
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>
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>