Final answer:
When an event occurs on a widget, the appropriate method of the event listener object is executed. This is a fundamental concept in programming for user interface interactions like mouse clicks or keypresses.
Step-by-step explanation:
When an event occurs on a widget, the appropriate method of the event listener object is executed. In programming, particularly in the context of graphical user interfaces, a widget is a component that users can interact with, such as a button or a text field. An event could be a user action like a mouse click or a keypress. The event listener is code designed to detect these events and trigger specific behavior in response.
In many programming languages, particularly those used for web development, you define what should happen when an event occurs by attaching an event listener to a widget. Then, when the event occurs, the associated method is called, executing any code within it to perform a task like updating the user interface or processing user input.
For example, in JavaScript, you might add an event listener to a button so that when it is clicked, it calls a method to update a count display:
button.addEventListener('click', updateCount);