Asif's blog

30 Days of JAVASCRIPT #14/30

Shaik Asif's photo
Shaik Asif
·

2 min read

Error Handling in JS

Error handling is an essential part of programming, and JavaScript provides several ways to handle errors. In this blog post, we will discuss how to handle errors in JavaScript using try/catch statements and custom error classes.

Try/Catch Statements

A try/catch statement is used to handle errors in JavaScript. It allows you to test a block of code for errors and handle them gracefully without breaking your code. The try block contains the code that might throw an error, and the catch block contains the code that handles the error.Here is an example code that demonstrates the use of try/catch statements:

try {
  // Some code that might throw an error
} catch (error) {
  // Code that handles the error
}

In the above code, we use a try/catch statement to handle errors in JavaScript. We put the code that might throw an error in the try block and the code that handles the error in the catch block.

Custom Error Classes

JavaScript also allows you to create custom error classes to handle specific types of errors. Custom error classes can be useful when you want to provide more information about an error or when you want to handle errors in a specific way.Here is an example code that demonstrates the use of custom error classes:

class CustomError extends Error {
  constructor(message) {
    super(message);
    this.name = "CustomError";
  }
}

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

try {
  divide(10, 0);
} catch (error) {
  if (error instanceof CustomError) {
    console.log(error.message);
  } else {
    console.log("An error occurred:", error);
  }
}

In the above code, we define a CustomError class that extends the built-in Error class. We then define a divide() function that throws a CustomError if the second argument is zero. We use a try/catch statement to catch the error and handle it. If the error is a CustomError, we print its message to the console. Otherwise, we print a generic error message.

Conclusion

Error handling is an essential part of programming, and JavaScript provides several ways to handle errors. Try/catch statements allow you to test a block of code for errors and handle them gracefully without breaking your code. Custom error classes allow you to handle specific types of errors in a specific way. By understanding and using these concepts, developers can write more maintainable and scalable JavaScript code.

JavaScript