Chrome Developer Tools. Tools for Web Developers Chrome DevTools is a set of authoring, debugging, and profiling tools built into Google Chrome. Open DevTools Select More Tools > Developer Tools from Chrome's Main Menu.Right-click a page element and select Inspect.Press Command+Option+I (Mac) or Control+Shift+I (Windows, Linux). Discover DevTools Device Mode Build fully responsive, mobile-first web experiences. Elements panel Iterate on the layout and design of your site by freely manipulating the DOM and CSS. Console panel Log diagnostic information during development or interact with the JavaScript on the page.
Sources panel Debug your JavaScript using breakpoints or connect your local files via Workspaces to use DevTools as a code editor. Network panel Optimize page load performance and debug request issues. Performance panel (previously Timeline panel) Improve the runtime performance of your page by recording and exploring the various events that happen during the lifecycle of a site. Memory panel (previously Profiles panel) Get Started with Debugging JavaScript in Chrome DevTools This tutorial teaches you the basic workflow for debugging any JavaScript issue in DevTools.
Read on, or watch the video version of this tutorial, below. Step 1: Reproduce the bug Finding a series of actions that consistently reproduces a bug is always the first step to debugging. Click Open Demo. The demo opens in a new tab. Step 2: Get familiar with the Sources panel UI DevTools provides a lot of different tools for different tasks, such as changing CSS, profiling page load performance, and monitoring network requests.
Open DevTools by pressing Command+Option+I (Mac) or Control+Shift+I (Windows, Linux). The Sources panel UI has 3 parts: The File Navigator pane. Step 3: Pause the code with a breakpoint A common method for debugging a problem like this is to insert a lot of console.log() statements into the code, in order to inspect values as the script executes. The console.log() method may get the job done, but breakpoints can get it done faster. Chrome DevTools Overview. Learning Chrome Web Developer Tools. Released All major browsers include developer tools, which enable developers to examine the code of a webpage or app, as well as run tests and evaluate metrics related to that code.
Chrome Developer Tools (DevTools for short) is the industry standard. Explore how the tools work in actual testing and debugging scenarios and get an expanded toolbox for your day-to-day work. This course teaches the most widely used parts of DevTools, using sample files to walk through identifying issues and bugs, fixing them, and then verifying that they've been fixed. Each chapter digs into a different tool, including the Console, Elements panel, and Network panel, exploring how it's useful and when to use it. Topics include: Setting up your testing and debugging environment Customize the display of Chrome Developer Tools Inspecting elements and styles Using the Console Opening source files in the Sources panel Identifying code that slows page loading Emulating mobile connections Skill Level Intermediate.
Chrome Developer Tools: Best resource for learning advanced features? Learn How To Debug JavaScript with Chrome DevTools – codeburst. That’s the basic idea of stepping through code.
If you look at the code in get-started.js, you can see that the bug is probably somewhere in the updateLabel() function. Rather than stepping through every line of code, you can use another type of breakpoint to pause the code closer to the location of the bug. Line-of-code breakpoints are the most common type of breakpoint. When you’ve got a specific line of code that you want to pause on, use a line-of-code breakpoint. Try it now: Look at the last line of code in updateLabel(), which looks like this: label.textContent = addend1 + ' + ' + addend2 + ' = ' + sum; To the left of this code, you can see the line number of this particular line of code: 32. Click the Resume script execution button: The script continues executing until it reaches the line of code you placed the breakpoint on.