在方法参数内创建构造函数

Question

 class Test {

  int a, b;

  Test (int i, int j){

  a = i;
  b = j;
  }
  boolean equalTo( Test o){

  if(o.a == a && o.b == b) return true; else return false; 

  }

  }

Im confused you can create an object of of constructor inside method parameter? I was reading a java textbook and boolean equalTo( Test o) they assigned Test value to o. My second question is, is there another time where u can put a class inside a method?

Answer 1

When we define method, the parameters that the method accepts can be a primitive value or a reference to an object with certain classes. Reference to an object is not creating an object. Every time you want to create an object of certain class, you would have to have the new keyword follow by class name and their constructor parameters.

When you are making a method, you can accept any reference of any class in the parameters. You make a method that accept references of other classes when you want to access other class information of calling their methods.

I would recommend to try this tutorial to get a better understanding of Object-Oriented Programming. https://www.w3schools.com/java/java_oop.asp

When you passed object with class Test to the method equalTo , every information of the passed object stays in the same location in virtual memory, only the reference is given to the method. With reference, we can access or manipulate the passed object without having the whole data structure being copied from the memory.