With this function you can check to see if a key is held down or not. Unlike the keyboard_check_pressed or keyboard_check_released functions which are only triggered once when the key is pressed or released, this function is triggered every step that the key is held down for. The function will take a keycode value as returned by the function ord() (only capital letters from A-Z or numbers from 0-9), or any of the vk_* constants listed on the main Keyboard Input page.
|key||The key to check the down state of.|
x -= 5;
The above code will check to see if the arrow key is being pressed and move the instance 5 pixels left every step that it returns true.