JavaScript Functions & Methods - Chapter 5 & 6 - PDF

CHAPTER 5: JavaScript Functions 1. How can you call a function in JavaScript? - By using its name followed by parentheses 2. What does the return keyword do in a function? - It specifies the value to be returned 3. What is required when defining a function? - A name, parentheses, and...

CHAPTER 5: JavaScript Functions 1. How can you call a function in JavaScript? - By using its name followed by parentheses 2. What does the return keyword do in a function? - It specifies the value to be returned 3. What is required when defining a function? - A name, parentheses, and a code block 4. Can functions call other functions? - Yes, functions can call other functions 5. How do you integrate functions with HTML? - Use HTML events like onLoad 6. What is a real-world example of using functions? - Validating form inputs in HTML 7. How do you pass multiple arguments to a function? - Separate them with commas inside the parentheses 8. What is local variable scope? - Variables accessible only within a function 9. Why are functions useful in large programs? - They help make code modular and maintainable 10. What is an advantage of modular functions? - They make debugging easier 11. Which of the following is the correct way to write a JavaScript comment? - // This is a comment 12. What is a function argument? - A value passed to a function during a call 13. How do you define a basic JavaScript function? - Using the function keyword 14. How can a function be used for interactivity? - By linking it to HTML events like onClick 15. What determines if a variable is local or global? - The place where it is declared 16. How do you handle errors in a function call? - Use conditional checks before calling functions 17. What is the main purpose of a function in JavaScript? - To organize code into reusable segments 18. What is global variable scope? - Variables accessible throughout the code 19. What happens if no return value is specified? - The function returns undefined 20. How can you fix a scope-related error? - Declare the variable in the global scope CHAPTER 6: Built-in JavaScript Method 1. How can you format a number to two decimal places? - Use the toFixed(2) method. 2. What does the sqrt() method do? - Returns the square root of a number. 3. What does the isNaN() method check? - Whether a value is not a number. 4. What does the map() array method do? - Creates a new array with results of a function. 5. How do you convert a string to lowercase? - Use the toLowerCase() method. 6. Which method is used to check if a string starts with a specific substring? - startsWith() 7. What does the split() string method do? - Converts a string into an array. 8. What does the parseInt() method do? - Converts a string to an integer. 9. Which method encodes a URI? - encodeURI() 10. What is the purpose of the concat() string method? - Combines two or more strings. 11. How is a method different from a function? - A method is attached to a class or object. 12. What is a built-in JavaScript method? - A predefined function provided by JavaScript. 13. How can you replace all occurrences of a substring? - Use the replaceAll() method. 14. Which method converts an array to a string? - join() 15. What does the every() array method do? - Checks if all elements pass a condition. 16. Which method creates a date object from milliseconds? - Date(milliseconds) 17. What is a major risk of using eval()? - Security vulnerabilities like code injection. 18. How can you find the last occurrence of a value in an array? - Use the lastIndexOf() method. 19. What is the purpose of the eval() method? - Executes a string as JavaScript code. 20. What is the difference between encodeURI() and encodeURIComponent()? - encodeURIComponent() excludes more characters. CHAPTER 7: The Document Object Model (The DOM) 1. How can you append a newly created element to a parent element in the DOM? - parentElement.appendChild(newElement) 2. What does querySelectorAll() do? - Selects all elements matching a selector. 3. What is the DOM? - A logical tree structure for HTML documents. 4. What is the navigator object used for? - Provides information about the browser. 5. What is the purpose of the id attribute? - Assigns a unique identifier to an element. 6. What does querySelector() do? - Selects the first element matching a selector. 7. What does the innerHTML property of a DOM element do? - Sets or retrieves the content inside an element. 8. How can you create a new HTML element in the DOM using JavaScript? - document.createElement() 9. Which JavaScript method is used to select an HTML element by its id? - document.getElementById() 10. What does the DOM represent in a web page? - The structure of an HTML document as an object model. 11. How do you select an element with a specific ID? - Use \#id in the selector. 12. How can you navigate to a new page using JavaScript? - Modify the location.href property. 13. What is the location object used for? - Represents the URL of the current page. 14. What does the \ tag contain? - Metadata for the page. 15. What does the \ tag do? - Creates a form for user input. 16. How can you dynamically change the DOM with JavaScript? - Use methods like querySelector() and.style. 17. What is the \ tag used for? - Contains inline content. 18. Which method retrieves a list of all elements in the DOM that match a specified CSS selector? - document.querySelectorAll() 19. What does the history object in the BOM do? - Allows navigation through the browser history. 20. Which of the following can be used to add an event listener to a DOM element? - addEventListener() CHAPTER 8: Interactive Content and Event Listener 1. What event captures the parent element of a button? - event.target.parentNode 2. What CSS property is essential for element animation? - position: absolute 3. What event fires when the mouse enters an element and its children? - onmouseover 4. Which event is fired after an element is loaded? - onload 5. What is commonly used for form validation? - Event handlers 6. What method prevents pasting invalid characters into an input box? - onpaste=\"return false\" 7. What is used to log event properties in the console? - console.log(event.target) 8. What event is triggered when a mouse hovers over an element? - onmouseover 9. What prevents invalid inputs in a number field? - onkeypress=\"return isNumber(event)\" 10. What triggers onchange events? - When input value changes 11. How do you add an event listener dynamically? - Use addEventListener() 12. Which function is used for animations? - animate() 13. What enables interactive content on web pages? - Changing the DOM based on user interactions 14. What event fires when a mouse leaves an element? - onmouseleave 15. What property identifies the HTML element that fired an event? - event.target 16. What does addEventListener() allow you to do? - Add multiple functions to the same event 17. Which mouse event is triggered on a double click? - ondblclick 18. Which event triggers when an input box loses focus? - onblur 19. Which key event ensures only valid characters are entered? - onkeypress 20. What is the default event propagation mode? - Bubbling