size of array

[ming ming]

how can i add the size of an array when it reaches it maximum???

    
 public class Test{
  String name;
  public void setName(name){
   this.name=name;
  }
public String getName(){
  return name;
  }
}
 
  public class TestTest{
  int amount=0
  int size=2;
  Test[]test=new Test[size];
  public void setTest(String name){
    test[amount]=new Test();
    test[amount].setName(name);
    amount++;
  }
}
 
  public class MainTest{
  public static void main(String [] args){
   TestTest z=new TestTest();
   z.setTest("xxx");
   z.setTest("www"); //if i add more how can i add more.
 }
}

[vinod balaji]

declare the amount variable as static. then it works fine

[ming ming]

i need to use a loop in the setTest method to make it auto increase the size of the array....but when i use a loop it will only show the first input....
any idea how to solve that?

[Arno Reper]

Hi,
first of all, you could take a look how Sun did in the ArrayList source file.
Second, you make another array with for example twice the length of your full array and then you use arraycopy to transfert the data to the new one.

 
Object[]myFull = new Object[3]; //imagine its full...
Object[]myNewOne = new Object[(myFull.length*2)];
System.arraycopy(...); //watch how the use it ;-)
myFull = myNewOne ;    
   

you could also do like that :

Object[]myFull = new Object[3];  
for (int i = 1 ; i<XXX;i++){
     if (myFull.isFull()){ 
                         Object[]myNewOne = new Object[(myFull.length*2)];
                         System.arraycopy(...); //watch how the use it ;-)
                         myFull = myNewOne ; 
                         myFull[i]= "Hello";
    }else myFull[i]= "Arno";
}

I hope it help,
Arno
[ May 26, 2006: Message edited by: Arno Reper ]

[Arno Reper]

ps : its nicer to write that with a static field...
like :

  
public static int size = 8;
new Object[8];
  

arno