How does System.out.print() work?

Question

I have worked with Java for a quite a long time, and I was wondering how the function System.out.print() works.

Here is my doubt:

Being a functi

Answer 1

You can convert anything to a String as long as you choose what to print. The requirement was quite simple since Objet.toString() can return a default dumb string: package.classname + @ + object number.

If your print method should return an XML or JSON serialization, the basic result of toString() wouldn't be acceptable. Even though the method succeed.

Here is a simple example to show that Java can be dumb

public class MockTest{

String field1;

String field2;

public MockTest(String field1,String field2){
this.field1=field1;
this.field2=field2;
}

}

System.out.println(new MockTest("a","b");

will print something package.Mocktest@3254487 ! Even though you only have two String members and this could be implemented to print

Mocktest@3254487{"field1":"a","field2":"b"}

(or pretty much how it appears in the debbuger)