There are several ways to debug JavaScript code in pure JavaScript, without the use of any additional tools or libraries. Some of the most common methods include:
- console.log(): This is one of the most basic and commonly used methods for debugging in JavaScript. You can use console.log() to print out the values of variables, objects, or any other expressions to the browser’s console.
- The debugger statement: The debugger statement is used to halt execution of JavaScript code and open the browser’s developer tools. This allows you to inspect the state of the code at the point where the debugger statement is executed.
- The Error object: JavaScript has a built-in Error object that you can use to raise an error and halt execution of the code. You can then inspect the stack trace in the browser’s developer tools to see where the error occurred.
- Using breakpoints: Most modern browsers allow you to set breakpoints in your code, which pause execution at a specific line. This allows you to inspect the state of your code and variables at that point.
- Use of assertion functions: Assertion functions are functions that check if a certain condition is true. If the condition is false, the assertion function raises an error, which can be caught and logged to the console.
In conclusion, there are several ways to debug JavaScript code in pure JavaScript, including console.log(), the debugger statement, the Error object, using breakpoints, and using assertion functions. The method you choose will depend on your specific debugging needs and the type of problem you are trying to solve.