Chapter 6.2: Handling Errors

Programmers often want to bypass errors because they expect them to happen. That’s perfectly fine, some operations, like reading a file or taking the square root of a negative number, are naturally prone to failure.

GLang provides a safe way to handle these situations using try and catch.

try {
    1 / 0; # error!
} catch error {
    bark("Some error occurred: " + error);
}

In this example, the try block runs first. If an error occurs, GLang automatically jumps to the catch block. The catch block takes an identifier (in this case, error) that stores a string describing what went wrong.

When this code runs, you’ll see something like:

Some error occurred: division by zero

After handling the error, the program continues running normally. In essence, try and catch tell GLang, "Attempt this code, and if it fails, handle the issue gracefully before moving on."

Your Challenge 🤔

Use try and catch to attempt to access an undefined variable named y. Define the variable with the value 10 if it fails to access it.

Answer

try {
    y;
} catch error {
    obj y = 10;
}