My React Journey: Day 17

Error Handling and Debugging
Errors are inevitable during program execution, but they can be effectively managed with proper handling techniques. This ensures the program doesn't crash unexpectedly and provides meaningful feedback to users.

What is an Error?
An error is an object that represents a problem that occurs during program execution.
Errors can interrupt the flow of the program if not handled correctly.

Common Types of Errors:

1. Network Errors: Issues with establishing connections (e.g., API calls fail).
2. Promise Rejection: Unhandled promises result in rejected states.
3. Security Errors: Issues related to permissions, access, or other security restrictions.

Error Handling Methods
try...catch...finally Structure:
1.try{ } block:

• Contains code that might throw an error.

2.catch { } block:

• Captures and handles any errors thrown in the try block.
• Use console.error instead of console.log for better visibility in debugging.

3.finally { } block (optional):

• Always executes, regardless of whether an error was caught.
• Commonly used for cleanup tasks (e.g., closing files, releasing resources).

** Examples**

General Error Handling

try {
    console.log(x); // Throws ReferenceError because 'x' is not defined
}
catch (error) {
    console.error(error); // Outputs: ReferenceError: x is not defined
}
finally {
    console.log("This always executes");
}

console.log("You have reached the end!");

Handling User Input Errors

try {
    const dividend = Number(window.prompt("Enter a dividend: "));
    const divisor = Number(window.prompt("Enter a divisor: "));

    if (divisor === 0) {
        throw new Error("You can't divide by zero!");
    }
    if (isNaN(dividend) || isNaN(divisor)) {
        throw new Error("Values must be numbers.");
    }

    const result = dividend / divisor;
    console.log(result);
}
catch (error) {
    console.error(error.message); // Logs the custom error message
}
finally {
    console.log("You have reached the end");
}

Best Practices for Error Handling

1.Use Descriptive Error Messages:

• Make errors easy to understand for debugging and user feedback.

• Example: "Cannot connect to the server" instead of "Network Error".
  2.Use finally for Cleanup Tasks:

• Always release resources like file handles, database connections, etc.

3.Catch Specific Errors:

• Avoid overly generic catch blocks; handle different errors appropriately.
• Example:

try {
    // Code
}
catch (error) {
    if (error instanceof TypeError) {
        console.error("Type Error:", error.message);
    } else {
        console.error("General Error:", error.message);
    }
}

4.Avoid Silent Failures:

• Always log or communicate the error instead of suppressing it silently.

Reflection

What I Learned:

• How to use try...catch...finally to manage errors gracefully.
• Importance of using console.error for debugging.
• Throwing custom errors with meaningful messages.

Slow & Steady Wins The Race!