Selenium - OOPs - Constructors

Something about constructors in Java:
Note: It is possible to use the same variable names for 

the constructor which is same as that of the Global 

variables. In that case you can still get the correct 

output by using the "this" operator for the global 

variables within the constructor.
public class operator{
int i;
int j;
//Parameterized constructor
public operator(int i,int j){
this.i=i; //here you can see that the variable i is same
this.j=j;//here this.j refers to global variable and j 

//refers to the passed variable name and passed j can 

//be called in other java file through the object 

//reference.
}
//Blank Constructor
public operator(){
System.out.println("World Here Hello How are 

you?")
}
public static void main(String[args]){
System.out.println("Hello World")
}

Note:
When you use a parameterized constructor make 

sure that the variable names are different, because it 

is possible that a global variable having the same 

name as that of the local variable will lead to 

confusion for selenium and it will give a wrong 

output but no message that it is wrong, thus leading 

to difficulties in debugging. Therefore the above said 

practice must be followed when using constructors. 

How is constructors related to testing?
In testing we write many functions inside a class file 

of java. When we do so each function might 

represent an action of the test case of the application.
Each such action can have variables that needs to be 

initialized through constructors and these 

constructors can be called in other java files (In 

general testscripts). So each java file is a testscript 

and they can call any global constructor from any 

other java file.