new ArrayList<int>() failing in Java

Question

I have the following code:

List<int> intList = new ArrayList<int>();
for (int index = 0; index < ints.length; index++)
{
    intList.add(ints[index]);
}

It gives me an error...

Syntax error on token "int", Dimensions expected after this token

The error occurs on the line starting with List. Can someone explain why I am getting the error?

Answer 1

Generics in Java are not applicable to primitive types as in int. You should probably use wrapper types such as Integer:

List<Integer> ints = ... 

And, to access a List, you need to use ints.get(index).

Answer 2

You can only use an Object type within the <> section, whereas you're trying to use a primitive type. Try this...

List<Integer> intList = new ArrayList<Integer>(); 

You then need to access the values using intList.get(index) and intList.set(index,value) (and also intList.add(value) as you are trying to do)

Answer 3

you should use Integer instead of int because lists requires object not primitive types. but u can still add element of type int to your Integer list