Try-catch blocks are an essential feature in TypeScript for handling runtime errors gracefully. They allow developers to anticipate and manage potential exceptions, ensuring robust and reliable code.

Basic Syntax

The structure of a try-catch block in TypeScript is straightforward:

try {
    // Code that might throw an error
} catch (error) {
    // Error handling code
}

How It Works

When an error occurs within the try block, the execution immediately jumps to the catch block. The catch block receives the error object as a parameter, allowing you to handle or log the error appropriately.

Practical Example

Here's a simple example demonstrating the use of try-catch in TypeScript:

function divideNumbers(a: number, b: number): number {
    try {
        if (b === 0) {
            throw new Error("Division by zero is not allowed");
        }
        return a / b;
    } catch (error) {
        console.error("An error occurred:", error.message);
        return NaN;
    }
}

console.log(divideNumbers(10, 2));  // Output: 5
console.log(divideNumbers(10, 0));  // Output: NaN (with error message in console)

Best Practices

Use specific error types when possible for more precise error handling.
Avoid using try-catch blocks for flow control; reserve them for exceptional cases.
Keep the code inside try blocks focused on the operations that might throw errors.
Consider using Custom Error Types for more detailed error information.

Advanced Usage: Multiple Catch Blocks

TypeScript allows you to use multiple catch blocks to handle different types of errors:

try {
    // Code that might throw different types of errors
} catch (error) {
    if (error instanceof TypeError) {
        // Handle TypeError
    } else if (error instanceof RangeError) {
        // Handle RangeError
    } else {
        // Handle other errors
    }
}

Integration with Promises

When working with asynchronous operations, you can combine try-catch blocks with Promises in TypeScript or Async/Await in TypeScript for effective error handling in asynchronous code.

Conclusion

Try-catch blocks are a fundamental tool for error handling in TypeScript. They help create more resilient applications by allowing developers to gracefully manage exceptions. When used judiciously, they can significantly improve the robustness and reliability of your TypeScript code.

For more advanced error handling techniques, explore Error Handling with Promises in TypeScript.