Consider the following JavaScript code: document.addEventListener('keypress', function(event) { console.log('Key pressed:', event.key); }); What does this code do?
A). A. Adds a click event listener to the document
B). B. Adds a keypress event listener to the document
C). C. Removes a keypress event listener from the document
D). D. Checks if a key is pressed while hovering over an element
What is the purpose of the removeEventListener() method in JavaScript?
A). A. To add event listeners to HTML elements
B). B. To detach event listeners from HTML elements
C). C. To prevent event propagation in event handling
D). D. To modify HTML content dynamically
Which event occurs when a user submits an HTML form?
A). A. onsubmit
B). B. onmouseover
C). C. onkeydown
D). D. onclick
What is the purpose of an event in JavaScript?
A). A. To add styles to HTML elements
B). B. To handle user interactions and browser actions
C). C. To define function names
D). D. To create animations on web pages
Which statement accurately describes JavaScript event bubbling?
A). A. It refers to the downward propagation of events from parent elements to child elements.
B). B. It refers to the upward propagation of events from child elements to parent elements.
C). C. It refers to the simultaneous firing of multiple events on the same element.
D). D. It refers to the automatic removal of event listeners after an event is triggered.
What is the purpose of the oninput event in HTML?
A). A. To track changes in form inputs
B). B. To detect mouse movements
C). C. To determine when an element is loaded
D). D. To handle form submissions
Which method is used to remove an event listener from an HTML element in JavaScript?
A). A. removeEventListener()
B). B. detachEvent()
C). C. removeEvent()
D). D. clearEventListener()
What is the primary purpose of JavaScript functions?
A). A. To style web pages
B). B. To provide structure to HTML elements
C). C. To create reusable code blocks
D). D. To define CSS styles for HTML
Which of the following correctly defines a JavaScript function?
A). A. function addNumbers(num1, num2) { return num1 + num2; }
B). B. function = addNumbers(num1, num2) { return num1 + num2; }
C). C. function addNumbers(num1 + num2) { return num1 + num2; }
D). D. function addNumbers(num1, num2) => { return num1 + num2; }
What does the preventDefault() method do in JavaScript event handling?
A). A. Stops event propagation to parent elements
B). B. Prevents the default behavior associated with an event
C). C. Detaches event listeners from elements
D). D. Clears the event queue