Error Handling in JavaScript

JavaScript provides built-in mechanisms to handle errors, making your code more robust and fault-tolerant. The most common approach is using the try...catch statement.

🛠️ try...catch Syntax

try {
    // Code that might throw an error
    let result = riskyFunction();
    console.log(result);
} catch (error) {
    // Code to run if an error occurs
    console.error("❌ Error:", error.message);
}

⚠️ Common Error Example

try {
    nonExistentFunction(); // This will throw a ReferenceError
} catch (err) {
    console.error("Caught error:", err);
}

✅ Optional finally Block

Use finally to run code after try/catch regardless of the outcome.

try {
    console.log("Trying something risky...");
} catch (err) {
    console.error("Caught an error");
} finally {
    console.log("Always runs this block.");
}

🚨 Throwing Custom Errors

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

try {
    console.log(divide(10, 0));
} catch (e) {
    console.error("Custom Error:", e.message);
}

📦 Async Error Handling

Use try...catch inside async functions for asynchronous error handling.

async function fetchData() {
    try {
        const res = await fetch("https://api.example.com/data");
        const data = await res.json();
        console.log(data);
    } catch (err) {
        console.error("Fetch error:", err);
    }
}