public void setPunt(int index){
if(index >= 0 && index < PuntenLijst.size()){
x = 3;
y = 5;
}
}
I have got an array of object instances in an array list called PuntenLijst. With this method I want to use the index parameter to locate the object in the ArrayList and set the variables x and y that are defined in the object instance to 3 and 5.
This is how far I have gotten. Is there anyone who can help me out?
Thanks a lot!
Create a setX and setY method in your object. Use them to change the value.
public void setPunt(int index){
if(index >= 0 && index < PuntenLijst.size()){
PuntenLijst.get(index).setX(3);
.... setY(5);
}
}
public void setPunt(int index){
if(index >= 0 && index < PuntenLijst.size()){
(ClassOfObjects)PuntenLijst.get(index).x=3;
(ClassOfObjects)PuntenLijst.get(index).y=5;
}
}
Ask the list for the Punt stored at the given index: See http://docs.oracle.com/javase/6/docs/api/java/util/List.html#get%28int%29.
Then use the methods provided by the Punt class to modify its internal state. My guess is that it has a setX() and a setY() methods (it should have those if you need to change its coordinates, anyway).
Did you mean something like this?
ArrayList<Object> PuntenLijst= new ArrayList<>(); // your arrayList
public void setPunt(int index){
if(index >= 0 && index < PuntenLijst.size()){
Object myObj = PuntenLijst.get(index);
myObj.setX(3);
myObj.setY(5);
}
}
Check out the docs on ArrayList http://docs.oracle.com/javase/7/docs/api/java/util/ArrayList.html
In your case, you'd want to do the following:
if(index >= 0 && index < puntenLijst.size()){
puntenLijst.get(index).x = 3;
puntenLijst.get(index).y = 5;
}
Note the following changes: puntenLijst should not be capitalized. x and y must be public variables in order to assign values like above.
PutenLijst.get(index).x=3?