GDScript Assert

GDScript is a dynamically typed, high-level programming language used to create games and other interactive applications using the Godot game engine. One of the built-in functions of GDScript is assert(), which allows developers to check if a particular condition is true and immediately stop the execution of the program if the condition is false.

Syntax

assert(condition, "message")

• condition: The expression that you want to check for truth
• message: An optional string that will be displayed if the assertion fails

Usage

Using assert() is a good way to ensure that your code behaves as expected. For example, you might use assert() to check that a variable is not null, or that its value falls within a certain range. Here's an example:

func some_function(value):
    # Check that value is not null
    assert(value != null, "Value must not be null")
    
    # Check that value is between 0 and 100
    assert(value >= 0 and value <= 100, "Value must be between 0 and 100")
    
    # If all assertions pass, continue with the function
    # ...

If the assertion fails, the program will immediately stop executing and display an error message with the message string that you passed to assert(). This makes it easy to catch issues early in the development process and fix them before they cause further problems.

Conclusion

In summary, assert() is a powerful tool that you can use to ensure that your code behaves as expected. By checking conditions and immediately stopping the program if they're false, you can catch issues early and avoid more serious problems down the line. Remember to use assert() wisely, and always provide a helpful error message to aid in debugging.