java - Creating a variable name using a String value

Question

This is a simple question (I think)

Lets say I have this code (Assuming I have a dog class)

String name = "dog";
dog name = new dog();

How can I get java to recognize name as a String and name the object dog?

Answer 1

While you can do what you're trying in some scripting languages such as PHP (and this question is often asked by many PHP programmers who start Java), this is not how Java works, and in fact variable names are a much less important than you may realize and hardly even exist after code is compiled. What is much more important and what is key are variable references -- the ability to gain access to a particular object at a particular point in your program, and you can have Strings refer to objects easily by using a Map as one way.

For example

Map<String, Dog> dogMap = new HashMap<String, Dog>();
dogMap.put("Fido", new Dog("Fido"));

Dog myPet = dogMap.get("Fido");

Or you can gain references to objects in many other ways such as via arrays, ArrayLists, LinkedLists, or several other collectinos.

Edit
You state:

The thing is that in my code I am going to be using one method to create objects, the name of the object is arbitrary but I need it to be dynamic because it wont be temporary, so the actually name of the object has to change or I will be writing over the previously declared object.

This is exactly what I meant when I said that the name of the variable is not as important as you think it is. The variable name is not the "object name" (this really doesn't exist in fact).

For example if you create a dog in a variable named Fido, and then assign it to a new variable named spot, both variables, despite having different names will refer to the very same object:

Dog fido = new Dog;
Dog spot = fido; // now fido and spot refer to the same object

If you want to give a variable a "name" consider giving the class a name property:

class Dog {
   private String name;

   public Dog(String name) {
      this.name = name;
   }

   public String getName() {
      return name;
   }
}

Now you can give each Dog object its own (semi) unique name if you wish.