Question: How do you use a local variable in GameMaker?

Answer

Local variables in GameMaker are variables that are only accessible within the script or event in which they are declared. They are created at the start of the event or script and destroyed at the end. To declare a local variable, you simply assign a value to a new variable name using the var keyword.

Here is an example of how to use a local variable within a script:

// Example Script: CalculateArea.gml

function CalculateArea(width, height) {
    var area; // Declare a local variable
    area = width * height; // Assign a value to the local variable
    return area; // Return the value of the area
}

And here is how you might use a local variable within an object's event (for example, in the Step event):

// In the Step Event

var speedX, speedY; // Declaring local variables for this step
speedX = 4;
speedY = 3;

// Use the local variables to update the instance position
x += speedX;
y += speedY;

Using local variables is a good practice for keeping your code clean and avoiding conflicts with global variables or instance variables that may have the same name.