Which two code lines make this code work as required?

A developer is creating a simple webpage with a button. When a user clicks this button for the first time, a message is displayed.

The developer wrote the JavaScript code below, but something is missing. The message gets displayed every time a user clicks the button, instead of just the first time.

01 function listen(event) {

02 alert ( ‘Hey! I am John Doe’) ;

03 button.addEventListener (‘click’, listen);

Which two code lines make this code work as required? Choose 2 answers
A . On line 02, use event.first to test if it is the first execution.
B . On line 04, use event.stopPropagation ( ),
C . On line 04, use button.removeEventListener(‘ click” , listen);
D . On line 06, add an option called once to button.addEventListener().

View Answer

Answer: C,D