legacy way to do collections

[Arjun Srivastava]

A non-generic collection can hold anything i.e. not a primitive.
please elaborate this statement and give me an example of adding a primitive type here.

   
int i=5; //primitve type
List n=new ArrayList();
n.add(i);
n.add(new Integer(i));

above code compiles fine with 1.6 compiler

[Sudhakar Sharma]

Hi Arjun,

I think line 4 will not compile in pre-java 5.0 compiler,

In java 5.0 primitives are auto-boxed to their wrapper type, hence ok with that.

"A non-generic collection can hold anything i.e. not a primitive." is very implicit because collection generic or non-generic cannot hold primitives.

please confirm

thank you

[Arjun Srivastava]

Sudhakar Sharma wrote:
line 4 will not compile in pre-java 5.0 compiler

that means adding primitive type to a non generic collection is possible with 1.5 and 1.6?
are you sure?

[Abimaran Kugathasan]

Since, auto-boxing available from 1.5, the primitives can be auto boxed into wrapper objects and can be added into collections. That's why you can add primitives in the above example!

And, normally, they are speaking about non-generics, because, in generics version, you can defined them, for example

ArrayList<Integer> a = new ArrayList<Integer>()

So, they normally speak about, non-generic versions. Sudhakar Sharma is correct!

Arun, because of auto boxing, you able to add primitives, only objects can be added to collections!

[Arjun Srivastava]

Abimaran Kugathasan wrote:Since, auto-boxing available from 1.5

that means if we are using pre java 5 compiler it will shows an error on line 4?

[Abimaran Kugathasan]

Yes, check by compiling!

[Arjun Srivastava]

thanks sir for quick reply and clearing doubts.

[Abimaran Kugathasan]

You are Welcome!