Java: Array of primitive data types does not autobox

java generics autoboxing
David Koelle picture David Koelle · Feb 5, 2009 · Viewed 21.1k times · Source

I have a method like this:

public static <T> boolean isMemberOf(T item, T[] set)
{
    for (T t : set) {
        if (t.equals(item)) {
            return true;
        }
    }
    return false;
}

Now I try to call this method using a char for T:

char ch = 'a';
char[] chars = new char[] { 'a', 'b', 'c' };
boolean member = isMemberOf(ch, chars);

This doesn't work. I would expect the char and char[] to get autoboxed to Character and Character[], but that doesn't seem to happen.

Any insights?

Answer

Eddie picture Eddie · Feb 5, 2009

There is no autoboxing for arrays, only for primitives. I believe this is your problem.

Related questions

How to create a generic array in Java?

Due to the implementation of Java generics, you can't have code like this: public class GenSet<E> { private E a[]; public GenSet() { a = new E[INITIAL_ARRAY_LENGTH]; // error: generic array creation } } How can I implement this while …

Read More
How do I get a class instance of generic type T?

I have a generics class, Foo<T>. In a method of Foo, I want to get the class instance of type T, but I just can't call T.class. What is the preferred way to get around it …

Read More
How do I make the method return type generic?

Consider this example (typical in OOP books): I have an Animal class, where each Animal can have many friends. And subclasses like Dog, Duck, Mouse etc which add specific behavior like bark(), quack() etc. Here's the Animal class: public class …

Read More