Functions, Methods, and Event Handling Quiz Quiz

Challenge your understanding of fundamental concepts in functions, methods, and event handling, including the differences between them, proper usage, parameter passing, and behavior in programming scenarios. Strengthen your knowledge for practical application and coding interviews with this focused quiz.

1. Function vs. Method Distinction

   Which statement best describes the key difference between a function and a method in programming languages that support both?

   1. A function can exist independently, while a method is associated with an object.
   2. Methods cannot return values, but functions can.
   3. Methods are only used for mathematical calculations, not functions.
   4. A function always takes arguments, but a method never does.

   Explanation: The correct answer is that functions can exist independently (outside of objects), whereas methods are functions that belong to an object or class. Methods can also take arguments and return values, just like regular functions, so the second and third options are incorrect. Both functions and methods can perform a variety of tasks beyond mathematical calculations, making the fourth option inaccurate.

2. Function Parameters and Default Values

   In many programming languages, what happens if you call a function that requires two arguments but provide only one, unless default values are specified?

   1. The function silently ignores the missing argument.
   2. An error or exception is raised due to missing arguments.
   3. The missing parameter will be randomly generated.
   4. The function will return zero automatically.

   Explanation: Calling a function with fewer arguments than required usually triggers an error or exception unless default values are provided, which is why the first option is correct. Functions do not assume zero for missing values (option two) nor generate random values (option three), and they generally do not ignore mandatory arguments (option four); all these would likely result in unintended behavior.

3. Event Handler Basics

   When attaching an event handler to a button click, what is typically required for the handler to execute successfully when the button is pressed?

   1. Changing the button's label to match the handler name.
   2. Creating a loop that continuously checks the button's state.
   3. Assigning a function to the button's click event property.
   4. Defining a variable with the same name as the event.

   Explanation: To make an event handler respond to a button click, you assign a function to the button's event property, such as 'onclick', which ensures the function runs when the event occurs. Simply defining a variable or changing the label does not connect the handler to the event. Polling the button state with a loop is inefficient and not a typical event-driven approach.

4. Method Calling Syntax

   Given an object called 'car' with a method 'start', which of the following shows the correct way to invoke the 'start' method?

   1. car.start()
   2. car-u003Estart[]
   3. start(car)
   4. start.car()

   Explanation: The common syntax for calling a method on an object is using the dot notation, as in 'car.start()'. The syntax 'start.car()' does not correctly reference the method from the object. 'car-u003Estart[]' might appear in some languages' class pointers but is not standard for method calls, and 'start(car)' would be used when 'start' is a separate function, not a method of the object.

5. Event Handling: Capturing and Bubbling

   In many event-driven systems, what does 'event bubbling' mean when a user clicks a nested element like a button inside a form?

   1. The event skips the innermost element and starts with the outermost parent.
   2. It means the event executes twice on the target element.
   3. 'Bubbling' refers to events that occur only with keyboard input.
   4. The event first triggers on the innermost element, then propagates outward to parents.

   Explanation: Event bubbling describes how events are first handled by the element directly interacted with (the innermost), then passed up to parent elements in the hierarchy. The event does not skip the innermost element and does not only apply to keyboard input. The event does not execute twice on the same element unless explicitly programmed to do so.