How do i create generic array in Java

Question

Due to the implementation of Java generics, you can't have code like this:

public class GenericSet<E> {
    private E a[];

    public GenericSet() {
        a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation
    }
}

How can I implement this while maintaining type safety?

One way to do it is :

import java.lang.reflect.Array;

class Stack<T> {
    public Stack(Class<T> clazz, int capacity) {
        array = (T[])Array.newInstance(clazz, capacity);
    }

    private final T[] array;
}

But it is very confusing to  understand

Answer 1

Generic array creation is not allowed in Java.

But, this might be a good solution to this unavailability :

class Stack<T> {
private final T[] array;
public Stack(int capacity) {
    array = (T[]) new Object[capacity];
 }
}

Hope this helps!!

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Thanks!!

Comments

how you will assign value to final variables ?

Answer 2

as first tip you cannot assign value to the final variables

and also you need to declare your method return type