Designing Games with Game Maker - YoYo Games

}
return (argument0*argument0);
To call a script from within a piece of code, just act the same way as when calling functions.
That is, write the script name with the argument values in parentheses.
With constructions
As indicated before, it is possible to read and change the value of variables in other instances.
But in a number of cases you want to do a lot more with other instances. For example,
imagine that you want to move all balls 8 pixels down. You might think that this is achieved by
the following piece of code
ball.y = ball.y + 8;
But this is not correct. The right side of the assignment gets the value of the y-coordinate of
the first ball and adds 8 to it. Next this new value is set as y-coordinate of all balls. So the
result is that all balls get the same y-coordinate. The statement
ball.y += 8;
will have exactly the same effect because it is simply an abbreviation of the first statement. So
how do we achieve this? For this purpose there is the with statement. Its global form is
with ()
indicates one or more instances. For this you can use an instance id, the name
of an object (to indicate all instances of this object) or one of the special objects (all, self,
other, noone). is now executed for each of the indicated instances, as if that
instance is the current (self) instance. So, to move all balls 8 pixels down, you can type.
with (ball) y += 8;
If you want to execute multiple statements, put curly brackets around them. So for example,
to move all balls to a random position, you can use