Debugging JavaScript Quiz

To pass the quiz, you must correctly answer at least 18 of the 20 questions below. # --quizzes-- ## --quiz-- ### --question-- #### --text-- What type of error occurs when a variable is used before it is defined? #### --distractors-- `SyntaxError` --- `LogicalError` --- `RangeError` #### --answer-- `ReferenceError` ### --question-- #### --text-- Which JavaScript statement can be used to intentionally pause the execution of your code for debugging purposes? #### --distractors-- `try...catch` --- `console.log()` --- `alert()` #### --answer-- `debugger` ### --question-- #### --text-- Which console method can be used to display data as a table? #### --distractors-- `console.log()` --- `console.warn()` --- `console.error()` #### --answer-- `console.table()` ### --question-- #### --text-- How can you inspect network requests in Chrome developer tools? #### --distractors-- By using the "Network Links" tab. --- By using the "Console" tab. --- By using the "Sources" tab. #### --answer-- By using the "Network" tab. ### --question-- #### --text-- What is the correct syntax for using `try...catch` in JavaScript? #### --distractors-- `try { ... } else { ... }` --- `try { ... } stack(catch) { ... }` --- `try { ... } error { ... }` #### --answer-- `try { ... } catch(error) { ... }` ### --question-- #### --text-- Which of the following is an example of a `SyntaxError`? #### --distractors-- Using a variable before it is declared. --- Using a variable twice in the same scope. --- Using a variable that is out of scope. #### --answer-- Missing a comma between elements of an array. ### --question-- #### --text-- What is the purpose of breakpoints in JavaScript debugging? #### --distractors-- Automatically correct code mistakes. --- Prevent code from being executed. --- Log messages to the console. #### --answer-- Pause execution at a specific point. ### --question-- #### --text-- What happens when the `throw` statement is executed? #### --distractors-- The program terminates immediately, ignoring all remaining code. --- The throw statement logs an error to the console but does not stop execution. --- It pauses code execution until resumed by disabling breakpoints. #### --answer-- An exception is thrown and the `catch` block (if present) is executed. ### --question-- #### --text-- Which method would you use to inspect variables or expressions during debugging in developer tools? #### --distractors-- `inspect()` --- `trace()` --- `console.error()` #### --answer-- `console.log()` ### --question-- #### --text-- What type of error will occur when the following code is executed? ```js function example() { console.log(a); let a = 5; } example(); ``` #### --distractors-- `FunctionError` --- `SyntaxError` --- Stack overflow error #### --answer-- `ReferenceError` ### --question-- #### --text-- Which tool is commonly used to step through code line by line during debugging? #### --distractors-- `console.log()` --- `alert()` --- `throw` statement. #### --answer-- Breakpoints in Developer Tools. ### --question-- #### --text-- What type of error occurs when attempting to access a property of `undefined`? #### --distractors-- `SyntaxError` --- `LogicalError` --- `RangeError` #### --answer-- `TypeError` ### --question-- #### --text-- What does the `finally` block do in a `try...catch` statement? #### --distractors-- Only executes if there's an error. --- Skips execution if `catch` is triggered. --- Exits the code block immediately. #### --answer-- Always executes, regardless of errors. ### --question-- #### --text-- What would be the result of running the following code? ```js const arr = []; arr.length = -1; ``` #### --distractors-- The code will throw a `SyntaxError`. --- The code will log an empty array to the console. --- The code will throw an out of memory error. #### --answer-- The code will throw a `RangeError`. ### --question-- #### --text-- Which of the following answers is true about the `debugger` statement in JavaScript? #### --distractors-- The `debugger` statement is always ignored by the browser. --- The `debugger` statement sends an error report to the server. --- The `debugger` statement always reloads the page and clears the console. #### --answer-- The `debugger` statement is ignored when the developer tools are not open. ### --question-- #### --text-- What is the primary purpose of "profiling" in JavaScript? #### --distractors-- To write unit tests for JavaScript functions and create profiles of code execution. --- To pause code execution and release the captured resources like memory and CPU. --- To convert JavaScript code into machine code for faster execution. #### --answer-- To identify performance bottlenecks by recording CPU usage, function calls, and execution time. ### --question-- #### --text-- What is a "watcher" in the context of debugging? #### --distractors-- A tool for pausing code execution. --- A built-in function for logging errors. --- A JavaScript method for handling exceptions. #### --answer-- A tool for monitoring the value of variables. ### --question-- #### --text-- When should you use `console.error()` instead of `console.log()`? #### --distractors-- To display table data. --- To log messages only during debugging. --- To log information about the browser. #### --answer-- To log error messages. ### --question-- #### --text-- What does the `Error()` constructor do in JavaScript? #### --distractors-- Logs error messages to the console. --- Runs code in a sandbox. --- Terminates the program. #### --answer-- Creates a new error object that can be thrown. ### --question-- #### --text-- What is the purpose of the `console.dir()` method in JavaScript? #### --distractors-- To create a separate directory for log files for individual error type. --- To generate a visual representation of the console output and save it in a pdf file. --- To stop the program execution and display an error message related to memory and CPU usage. #### --answer-- To output a hierarchical, interactive list of properties for a specified JavaScript object.