I am a new learner in Greenfoot. Can anyone help me with how I can add a counter so that my object changes images every n times the Act method is invoked?
avocasso wrote ...
2012/11/20
Add a counter to a code
public int counter = 0;
And then in the act method add
This might not be what you are looking for, but maybe it helps and gives you an idea of how it could be done. One thing this would only change the image once since I only added one setImage( image );
public void act()
{
if (counter == n)
{
setImage(the image you want to change to);
counter = 0;
}
else
{
counter++;
}
}
@Zamoth instead of this:
this would be better:
;)
public int counter = 0;
private int counter = 0;
Yes you are right I just forget thinking about wether I should make a reference private or public since I don't know what benefits you get from making it private. I know that other objects can't change the value of a private, but what benefits you get from that I don't know.
Btw thanks for correcting me (:
I know, but it's a better code design to make them private always, and let others access them using setter and getter methods. It's just like real life: if you need to make a painting, you don't want others to be able to mess around with it! :)
So SPower, I am not sure if I understand your approach. Are you suggesting that I have this:
01. public void act()
02. {
03. if (counter == n)
04. {
05. setImage(the image you want to change to);
06. private int counter = 0;
07. }
08. else
09. {
10. counter++;
11. }
12.}
No, I meant this:
which is just a bit improved from zamoht.
private int counter = 0;
public void act()
{
if (counter == n)
{
setImage(the image you want to change to);
counter = 0;
}
else
{
counter++;
}
}So I tried it, it works. Thanks ! But in the meantime my object changed images only one time every four times that the Act method is invoked, even though I specified counter == 4, in other word I wanted the object to change every 4 times the Act method is invoked. Is there a way to make the object doing the change continuously, ie after every 4 times go back to the initial image where we started from and do it over again?
To cycle through the images one per act method
Line 4 above is equivalent to
essentially getting the remainder of the incremented value divided by four.
// with instance field
private int counter=0;
// and in act
counter=(counter+1)%4;
if(counter==0)setImage("image1.png");
if(counter==1)setImage("image2.png");
if(counter==2)setImage("image3.png");
if(counter==3)setImage("image4.png");counter=(counter+1)-4*((counter+1)/4)
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