Skip to main content

Throw

The throw keyword raises an error that can be caught by try/catch.

Syntax​

throw "Something went wrong";
throw errorValue;

Throwing a String Error​

Validate method(age as int) {
    if (age < 0) {
        throw "Age cannot be negative";
    }
}

Catching a Thrown Error​

try {
    Validate(-1);
} catch (error) {
    Print(error);    // "Age cannot be negative"
}

Custom Error Types​

Define error classes and throw instances:

ValidationError class {
    message is "" as string;

    constructor public method(msg as string) {
        this.message is msg;
    }
}

// later...
throw ValidationError("Invalid input");

Next Steps​