Question

using loop, I can create

My cat is: Cat1
...
My cat is: Cat1

However, when I tried to use

  Cat ("cat"+i) = new Cat("Cat" + i);

I’m making mistakes….

So, what is the simplist way to correct my code to produce

cat1 ... cat10 cat instances?


public class TestCat{ 
  public static void main(String [] args){ 

 for (int i=1; i<10; i++){     
   //Cat ("cat"+i) = new Cat("Cat 1");
   Cat cat1 = new Cat("Cat 1");  
   System.out.println("My cat is:  " + cat1 ); 
  }
 } 
} 

class Cat{

 static String catName;
 public Cat(String catName){
   this.catName=catName;
 }
 public String toString(){
   return catName;
}
}

Sorry….I should say

How to create ten 10 Cat instances…..cat1, …cat2…..because in other languages, I can use “cat”||i = …, to create different varaibles, I wonder how I could do similar things in Java….

In other words, I want to name the instances I’m going to create by taking the loop information into account.

Answer 1

Use a collection if you don’t know how many cats you’ll have.

public class TestCat
{ 
  public static void main(String [] args)
  { 

    Cat[] cats = new Cat[10];    
    Vector catsUnlimited = new Vector(10);    
    Cat myCat = null;

    for (int i=1; i<11; i++)
    {     
    myCat = new Cat("Cat" + i); 
      cats[i-1]= myCat; 

      catsUnlimited.addElement(new Cat("Cat" + i));

      System.out.println("My cat is:  " + cats[i-1] ); 
    }

    System.out.println("Known cats");
    for (int x = 0; x < catsUnlimited.size(); x++)
    {        
     System.out.println("Cat #" + (x+1) + ":" +(Cat)catsUnlimited.get(x));
    }    
  } 
} 

Note: This code produces incorrect results and had me stumped until I looked closer at the Cat class.

My cat is:  Cat1
My cat is:  Cat2
My cat is:  Cat3
My cat is:  Cat4
My cat is:  Cat5
My cat is:  Cat6
My cat is:  Cat7
My cat is:  Cat8
My cat is:  Cat9
My cat is:  Cat10
Known cats
Cat #1:Cat10
Cat #2:Cat10
Cat #3:Cat10
Cat #4:Cat10
Cat #5:Cat10
Cat #6:Cat10
Cat #7:Cat10
Cat #8:Cat10
Cat #9:Cat10
Cat #10:Cat10

Here was the culprit:

public class Cat
{
     static String catName;

Remove the static and you are golden.