Why Does My JSFiddle Show a 'test not defined' Error, and How Can I Fix It?

Debugging a Broken JSFiddle: Resolving the "test not defined" Error

In this JSFiddle, despite having a button with an onclick handler, clicking the button does not trigger the alert. The console displays the error "test not defined." To understand this issue and its resolution, let's delve deeper into the JSFiddle settings.

Understanding JSFiddle's Wrap Settings

By default, JSFiddle wraps all JavaScript code in a function that executes once the page is fully loaded. This means that all variables and functions defined in the JavaScript code are local to this wrapping function and are not accessible in the global scope. Hence, the function test() used by the onclick handler is not recognized.

Resolving the Issue by Modifying Wrap Settings

To fix this issue, we need to modify the JSFiddle settings to disable code wrapping. Open the settings panel, navigate to the "JavaScript" tab, and under the "Wrap your code?" dropdown, select "no wrap." This ensures that the JavaScript code is executed immediately, and variables and functions are available in the global scope.

Updating the JSFiddle

Here's the updated JSFiddle with the no wrap setting: http://jsfiddle.net/zalun/Yazpj/1/

Notice that we also switched the framework to "No Library" since you are not using a JavaScript framework.

Conclusion

By adjusting the JSFiddle wrap setting, we resolved the "test not defined" error and enabled the button's onclick handler to work as intended. It's important to consider the impact of JSFiddle settings on code behavior and make the appropriate adjustments to ensure your code executes correctly.

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