Error Handling

try…catch

console.log("This is the start of the program");
try{
    console.log(a);
}
catch(err){
    console.log("The Error is: "+err);
}
console.log("This is the end of the program");

• Output

Throwing Errors

try {
    let a = 9 / 0;
    console.log(a); // Infinity
    if (!isFinite(a)) {
        throw new Error("Division by zero");
    }
} catch (error) {
    console.log(error.message); // Division by zero
}

<aside> 💡 JavaScript errors are objects with a base class of Error, including SyntaxError, ReferenceError, TypeError, etc., and custom errors can extend Error for specialized handling.

</aside>

Custom Error

class CustomError extends Error {
    constructor(message) {
        super(message);
        this.name = "CustomError";
    }
}
try {
    throw new CustomError("Something went wrong");
} 
catch (error) {
    console.error(error.name); // Output: CustomError
    console.error(error.message); // Output: Something went wrong
}

• Output