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Dipak Ahirav
Dipak Ahirav

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Top 4 JavaScript Debugging Tips for Beginners🐞

Debugging is an essential skill for any JavaScript developer. Learning how to effectively find and fix bugs can save you a lot of time and frustration. Here are four debugging tips to help beginners tackle JavaScript issues more efficiently. 🌟

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1. Use console.log() Wisely 🖥️

The console.log() method is a simple yet powerful tool for debugging JavaScript code. It allows you to print values to the console, helping you understand what your code is doing at various points.

Tips:

  • Print Variables: Use console.log() to print variable values and ensure they are what you expect.
  • Trace Execution: Add console.log() statements at different points in your code to trace its execution flow.
  • Format Output: Use string interpolation and object formatting for clearer output.

Example:

function calculateSum(a, b) {
  console.log(`a: ${a}, b: ${b}`); // Print input values
  const sum = a + b;
  console.log(`Sum: ${sum}`); // Print result
  return sum;
}

calculateSum(3, 5);
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2. Utilize Breakpoints in the Browser DevTools 🛠️

Modern browsers come with powerful developer tools (DevTools) that include a built-in debugger. Setting breakpoints in your code allows you to pause execution and inspect the current state.

Tips:

  • Set Breakpoints: Click on the line number in the Sources panel to set a breakpoint.
  • Step Through Code: Use the step buttons to move through your code line by line.
  • Inspect Variables: Hover over variables or use the Scope panel to inspect their values.

Example:

  1. Open DevTools (F12 or right-click -> Inspect).
  2. Go to the Sources panel.
  3. Set a breakpoint by clicking on a line number.
  4. Reload the page and use the debugger controls to step through the code.

3. Leverage Error Messages 📜

JavaScript error messages provide valuable information about what went wrong and where. Learning to read and understand these messages can help you quickly pinpoint issues.

Tips:

  • Read the Error Message: Pay attention to the error type and message.
  • Check the Stack Trace: The stack trace shows where the error occurred and the sequence of function calls that led to it.
  • Look Up Error Codes: If you're unsure about an error, look it up online for more information.

Example:

function divide(a, b) {
  if (b === 0) {
    throw new Error('Division by zero is not allowed');
  }
  return a / b;
}

try {
  divide(4, 0);
} catch (error) {
  console.error(error.message);
  console.error(error.stack); // Check stack trace
}
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4. Use Debugger Statements for Manual Breakpoints 🔍

The debugger statement acts as a manual breakpoint in your code. When the JavaScript engine encounters a debugger statement, it will pause execution if DevTools is open.

Tips:

  • Place Strategically: Add debugger statements in locations where you suspect issues.
  • Remove After Debugging: Make sure to remove or comment out debugger statements once you have resolved the issue.

Example:

function findMax(arr) {
  let max = arr[0];
  for (let i = 1; i < arr.length; i++) {
    debugger; // Pause execution here
    if (arr[i] > max) {
      max = arr[i];
    }
  }
  return max;
}

const numbers = [3, 7, 2, 9, 4];
findMax(numbers);
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By following these debugging tips, you'll be better equipped to identify and resolve issues in your JavaScript code. Remember, effective debugging is a skill that improves with practice. Happy coding! ✨

Start Your JavaScript Journey

If you're new to JavaScript or want a refresher, visit my blog on BuyMeACoffee to get started with the basics.

👉 Introduction to JavaScript: Your First Steps in Coding

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Top comments (1)

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jangelodev profile image
João Angelo

Hi Dipak Ahirav,
Top, very nice and helpful !
Thanks for sharing.