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
In JavaScript, what is the purpose of the addEventListener() method?
A). A. To create inline event handlers
B). B. To attach event listeners to HTML elements
C). C. To remove event listeners from HTML elements
D). D. To bind event handlers to parent elements
Which event is triggered when a user clicks on an HTML element?
A). A. onhover
B). B. onsubmit
C). C. onload
D). D. onclick
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
How can you prevent the default behavior of an event in JavaScript?
A). A. By using the event.preventDefault() method inside the event handler function
B). B. By using the event.stopPropogation() method inside the event handler function
C). C. By using the event.stopPropagation() method inside the event handler function
D). D. By using the event.defaultPrevented property inside the event handler function
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
How can you attach multiple event listeners to the same HTML element in JavaScript without overwriting existing ones?
A). A. By using the attachEvent() method
B). B. By using the addEventListener() method with the replace parameter
C). C. By assigning multiple functions directly to the element's event attributes (e.g., onclick, onmouseover)
D). D. By using the addEventListener() method multiple times for the same event
Consider the following HTML code: Which JavaScript code adds a click event listener to the button?
A). A. document.getElementById('myButton').onclick = function() { alert('Button clicked'); };
B). B. document.getElementById('myButton').addEventListener('click', function() { alert('Button clicked'); });
C). C. document.getElementById('myButton').click(function() { alert('Button clicked'); });
D). D. document.getElementById('myButton').on('click', function() { alert('Button clicked'); });
Which method is used to attach an event listener to an HTML element in JavaScript?
A). A. appendEvent()
B). B. addEventListener()
C). C. attachEvent()
D). D. bindEvent()
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; }