Dragonfly Cloud is now available in the AWS Marketplace - learn more

Question: How do you use a for loop in GameMaker?

Answer

For loops are commonly used in programming to repeat a block of code a certain number of times. In GameMaker, you can use for loops when you want to iterate through arrays, create repetitive tasks, or any time you need to execute code multiple times.

Here's the general syntax for a for loop in GameMaker's GML (GameMaker Language):

for (initialization; condition; iteration) { // Code to be executed each loop iteration }

Let's break down what each part means:

  • initialization: This is where you initialize your loop control variable. Commonly, you'll see something like var i = 0; which starts the counter at 0.
  • condition: The loop will continue to run as long as this condition is true. For example, i < 10 means the loop will run while i is less than 10.
  • iteration: After each loop iteration, this code runs. It's often used to increment the loop control variable, such as i++ to increase i by 1 each time.

Here's a concrete example of how a for loop might be used in GameMaker to initialize an array with values:

var myArray; myArray[9] = 0; // Create an array with 10 elements (0 to 9) for (var i = 0; i < 10; i++) { myArray[i] = i * 2; // Each element is assigned twice its index value }

In the above example, we declared an array named myArray and used a for loop to populate it with values that are double their respective indices.

For loops are a powerful tool in GameMaker for automating repetitive processes, handling data structures, or creating complex game mechanics without writing redundant code. Always ensure that your condition will eventually become false; otherwise, you'll create an infinite loop, which can cause your game to freeze or crash.

Was this content helpful?

White Paper

Free System Design on AWS E-Book

Download this early release of O'Reilly's latest cloud infrastructure e-book: System Design on AWS.

Free System Design on AWS E-Book

Switch & save up to 80% 

Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement. Instantly experience up to a 25X boost in performance and 80% reduction in cost