Is it possible to name a variable using a variable in Java?

Question

What I would like to do is have a loop that names a certain number of variables each time. So sometimes when I run the program, this loop will create say 3 variables a1, a2 & a3 but other times it could name more, eg (if this sort of thing were possible):

for(int i=1; i<=n;i++) {
    int ai = i;
}

So in the case (for i=1) the name of the int would be a1 and contains the int 1. This clearly won't work, but I was wondering if there was a way to achieve this effect -- or should I stop hacking and use a different data structure?

Thanks.

Also, this is just an example. I'm using it to create arrays.

Answer 1

No, this is not possible. Java has no way to construct symbols. However, you can use it to define variable-size arrays. For example:

int[] a = new int[n];
for(int i = 0; i < n; i++) {
    a[i] = i; 
}

Which seems like what you may want.

Answer 2

Map

Can you use an implementation of Map such as a HashMap ?

import java.util.HashMap;
import java.util.Map;


public class test {

    public static void main(String[] args) {

        //Fill your map structure
        Map<String, Integer> theMap = new HashMap<String, Integer>();
        for(int i = 1; i <= 100; i++) {

            theMap.put("a" + i, i);
        }

        //After this you can access to all your values
        System.out.println("a55 value: " + theMap.get("a55"));
    }
}

Program output:

a55 value: 55

Answer 3

Rather than trying to define variables a1, a2, a3, ... you can simply define a fixed size array:

int[] anArray = new int[10]; 

and refer to a[1], a[2], a[3],...

Answer 4

我只是制作一个数组数组，其中索引等于i值。