Explore key concepts of JavaScript debugging using breakpoints within browser developer tools. This quiz aims to help professionals and learners deepen their understanding of how to set, manage, and analyze breakpoints for efficient debugging strategies.
When trying to pause code only if a variable 'count' exceeds 10 during loop execution, which feature should you use in browser developer tools?
Explanation: A conditional breakpoint allows code execution to pause only if a particular condition is true, such as if 'count' is greater than 10. Logpoints simply log messages without pausing execution. DOM breakpoints are used to pause on specific changes in the Document Object Model, unrelated to variables' values. Watch expressions help monitor variables but do not automatically trigger a pause.
If you want your script to pause whenever a button's 'click' event is triggered, which debugging tool feature best achieves this?
Explanation: Event listener breakpoints specifically pause code execution when an assigned event (such as 'click') occurs on a particular element. Line-of-code breakpoints pause at a specified line regardless of events. XHR/fetch breakpoints are for network requests. The call stack viewer only shows the current stack and does not create breakpoints.
After hitting a breakpoint, which panel should you use to inspect the values of local and global variables at the paused execution point?
Explanation: The Scope panel displays the current values of variables in local and global contexts when paused. The Network panel shows resource requests, not variable states. Elements is for viewing and editing the page's structure, not your JavaScript variables. Performance focuses on analyzing runtime behavior and bottlenecks rather than variable inspection.
When debugging code that has been minified into one line, what tool helps you set breakpoints more effectively by improving readability?
Explanation: Pretty Print reformats minified or compressed code into a more readable, indented format, making it easier to set and manage breakpoints. Breakpoint Grouping organizes breakpoints but does not affect code legibility. The Watch Panel is only for tracking specific expressions. Source Mapping helps relate minified code to original sources but does not reformat the code in the current view.
If you want to execute the next function call entirely without stepping into its internal lines, which stepping option should you choose when paused at a breakpoint?
Explanation: Step over allows you to run the current function call as a whole and stop at the next line in the current function, avoiding the internal lines of the called function. Step into would enter the new function line by line. Step out resumes execution until the current function exits. Continue resumes execution until the next breakpoint but doesn't control stepping granularity.