How can you debug a website that is displaying incorrect data?

If debugging on front-end, implement conditional console logic to ensure that the end users does not encounter the console output.

1. Open Developer Tools: - Right-click on the webpage and select "Inspect" or "Inspect Element." Alternatively, you can press `Ctrl+Shift+I` (Windows/Linux) or `Cmd+Opt+I` (Mac) to open Developer Tools. 2. Navigate to the Console Tab: - In the Developer Tools window, find and click on the "Console" tab. This is where error messages and warnings are displayed. 3. Check for Errors: - Look for any error messages in red. These messages often provide information about what went wrong, including incorrect data or issues with scripts. 4. Log and Debug: - If you have access to the website's code, you can use `console.log()` statements in the JavaScript code to output specific values or messages to the console for debugging purposes.

The very initial point to start debugging is browser console. It gives many options to know the root cause of UI issues. While doing local development leverage console logs to log the data. - Debugger - Use file debugger where source code can be debugged adding breakpoints. - Network tab - where you can see the API calls and request/response data.

While relying solely on the browser console for debugging may seem basic, it remains a powerful and indispensable tool for developers. The console provides a real-time window into your web application's inner workings, allowing you to spot errors, log data, and trace the flow of your code. It's the go-to place for identifying JavaScript errors, warnings, and runtime issues. Furthermore, the console enables you to execute JavaScript commands on the fly, making it a versatile tool for testing and experimentation. So, never underestimate the browser console—it's often your first and best ally in diagnosing and resolving issues within your web application.

Console logging is crucial for debugging, involving the strategic placement of console.log() statements within the code to obtain real-time insights into variable values, data flow, and errors. This practice is vital for tracing the execution path and detecting anomalies in data processing logic. Developers leverage console logging to inspect variables, identify errors, and dynamically debug code during runtime.

L'utilisation des journaux (logs) du serveur est primordiale, car elle permet en premier lieu de corriger toutes les erreurs critiques qui ne remontent pas forcément en front (en raison de configurations du serveur ou autre), mais également pour traquer et corriger tous les "warning" et "notice" qui peuvent survenir sur des cas particuliers non anticipés. Toutes ces erreurs peuvent utiliser des ressources (ne serait ce que pour l'écriture en log), et les traiter permet ainsi d'optimiser votre code. C'est particulièrement vrai sur de grosses applications où les utilisateurs trouveront toujours moyen d'utiliser des cheminements auquel vous n'avez pas pensé, et donc testés.

Utilizing server logs is valid, alas a reactive measure. To be on the more proactive side you can install code monitoring and analysis tools like sentry, snyk, codeclimate or others, and be up to date with the possible issues, bad code, bad queries, duplications, etc.. Having these tools that give insights helps you act even before an issue arises.

When working with .Net web application or WordPress sites, rememeber that you can enable loggin features easily by toggling on it. Also for insite .net servers, try to enable log errors on ISS server configuration and also check windows error logs, sometimes there is information about your problem.

If you encounter specific error messages or need help interpreting logs, providing more details about the issue or error messages can help in offering more targeted assistance. Use command-line tools like cat, tail, less, or grep to view and search through log files.

Insert console.log statements in your JavaScript code to log data at different points. This can help pinpoint where the data might be getting corrupted.

Depending on the data source you’re working with it’s important to check a few things. If it’s a DB, check your connection. Make sure you have correct access/permissions to the db, table, collection, or store. To test that it’s working you can run a simple query and view results in cli or browser. If it’s an API, first check the documentation. Most API will require you to use an API key and/or authorization. To do my preliminary testing I like to use Postman. You can test your endpoint and ensure everything is working correctly before you move to code. When you have an issue always start with the trivial and move on to the next step. Do I have all my connection details correct? Did I misspell anything? Do I have a connection? Etc…

When fixing data display issues on a website, start by verifying the data at its source. I use SQL tools like MySQL Workbench for databases and Postman for API data to ensure accuracy. For websites using CMS like WordPress, utilize built-in tools and plugins like Query Monitor. For complex data processes (ETL), tools like Talend or Python scripts are the go-to. Also check data caching and synchronization, using Redis Desktop Manager for Redis and custom scripts for data sync issues. Chrome's developer tools are essential for general troubleshooting, and Git with GitHub for version control. This thorough approach helps identify and fix the root cause of data discrepancies, most of the time.

When dealing with problems like incorrect data display, I find it helpful to check data sources using Postman. This step allows me to quickly determine whether the issue lies in the back-end or front-end, helping to streamline the troubleshooting process.

Checking the data source is a crucial step in debugging. It becomes even more vital when your website is connected to a Content Management System (CMS), where users frequently update and add content. In such cases, data quality can sometimes be uncertain due to user contributions. Therefore, verifying the data source is essential to ensure that the information displayed on your website remains accurate and consistent.

If the data is pulled from a database or API, verify its accuracy and integrity. Look for any errors or inconsistencies in the data source itself. Use query tools or API documentation to understand the data structure and expected format.

You can use debugger statements at the offending lines of code. Then using the web inspector, you can step through the code and hover over the variables or properties to see what values they are storing.

Il est primordial, surtout dans un CMS modifié ou dans une solution développée 'from scratch', de s'assurer que la logique de code est sans faille, qu'il n'y a pas d'identifiant unique qui soit réécrit à la volée, de s'assurer que les tests soient juste et appliqués aux bonnes variables. Il est sinon facile d'afficher les informations d'une autre page, ou d'avoir un bloc qui n'est pas sensé s'afficher dans cette catégorie.

To avoid wasting a lot of time looking for logic errors, you should ecourages the code coverage to be over 80%. Unit testing is also a good helper to identify when broken endpoint or functionalities.

If the data is further manipulated by JavaScript or other client-side code, examine it closely. Look for errors in JavaScript code, especially in functions that handle data fetching, parsing, or display. Use browser developer tools like the console and debugger to monitor code execution and identify any errors.

The code logic refers to the sequence of rules, instructions, and algorithms written in a programming language that determine how a website or any software application operates. It governs how data is processed, manipulated, stored, retrieved, and displayed to users.

The first thing to look at is the network data and check what is returned when getting the data from the backend. If it is still wrong then we have to look at the logic in the back and recreate the scenario in the debug mode to follow the logic and see which part is doing wrong.

Our users are invaluable testers, offering diverse insights that can significantly enhance our web development efforts. They bring varied use cases, might use exotic devices, and hold unique expectations on how features should operate. As web developers, it's our responsibility to create websites that are fluid and convenient. This requires taking user feedback seriously and integrating it into our design and development process. Remember, user experience is paramount: a website without users is like a tree falling in an empty forest – it may exist, but its impact is lost."

User feedback removes the guesswork from analyzing visitor behavior on your site and reduces the communication barrier between you and your customers. Analyzing and acting upon user feedback often leads to enhancements in user satisfaction, product/service improvements, and overall better user experiences.

If you depend on user feedback than you are not developer who is ready for production. Developer who do not have power to be superuser is not real developer.

You may think a form on your site is intuitive, or that your date/time formats are, but you may have users from different regions, who may not find a simple date format intuitive and they may be entering data incorectly or worse in incompatibility with your database field. When you take that feedback into consideration you can work on implementing fallbacks and making your code more robust and cover even the edge cases.

I'd say the most important thing is to have a reliable team by your side. Like, for example, apart from having great back-end and front-end developers at my company, we also have a solid team of QA engineers. Because we understand that our clients don't need websites full of bugs, so we make sure we are responsible for the whole process and deliver outstanding results.

Other things to consider 1. Inspect the Data Source: Check the data source that the website is pulling information from. Make sure the data in the source is accurate and up to date. If the source is external, verify that it's providing the correct data. 2. Check the Backend Code: Examine the backend code responsible for fetching and processing the data. Look for any logic errors, incorrect data transformations, or issues with the database queries. Debugging tools and logging can be helpful here. 3. Review the Frontend Code: Inspect the frontend code that handles the data rendering. Look for any mistakes in how the data is being displayed or manipulated. Check for any data formatting or parsing errors.

If you are the website developer, check also with the website / product / project owner / client. Most of the time, the problem is from their side. Often time there are unclear feedbacks and false directions. #JustSaying

While web browsers offer a range of valuable debugging features, they may not always be the optimal choice for every task. It's worth exploring specialized browser extensions tailored to your specific debugging needs. For instance, if you're addressing accessibility concerns, dedicated tools like Axe excel in this area. On the other hand, when dealing with React-related issues, you'll find React Dev Tools to be a more precise and effective solution. By leveraging these specialized extensions, you can enhance your debugging efficiency and pinpoint issues with greater accuracy.

Easy checklist to avoid most errors: *Implement unit testing *Keep 80% or above of code coverage *Use pipelines to deploy your site, so you can integrate code/vulnerability testing. *Keep up to date your frameworks and third party plugins. *NEVER use non-stable software. *Set flag mechanism to turn on/off error logging. *Have a good teamwork. If you already have that list checked then feel happy to have a nice environment.