Parameterized Constructors v/s Setter and Getter function in JAVA.

In my opinion, there is only a syntax difference between parameterized constructors and setter function in JAVA. Both would be used to initialize the class variables with user-defined values.

In parameterized constructors, all the class variables can be initialized within one function (constructor) which is automatically invoked when a user creates an object of that class.

On the other hand, while using a Setter function. Each class variable should have its own setter method which needs to be invoked for each variable of that class.

Getter function is used to read/access the class variables. There are two methods to access/read a class variable using a return statement or without the return statement.

ClassA

/**
 * 
 */
package GetterSetter;

/**
 * @author ashok.kumar
 *
 */
public class ClassA 
{
	int roll;
	String name;
	public ClassA(int x, String y)
	{
		roll=x;
		name=y;
	}

}

ClassB

/**
 * 
 */
package GetterSetter;

/**
 * @author ashok.kumar
 *
 */
public class ClassB 
{
	int rollB;
	String nameB;
	
	
	// Setter function for 'rollB'
	void setrollB(int x)
	{
		rollB=x;
	}
	
	// Getter function for 'rollB'
	void getrollB()
	{
		System.out.println(rollB);
	}
	
	
	// Setter function for 'nameB'
	 void setnameB(String y)
	 {
		 nameB=y;
	 }
	 
	 
	// Getter function for 'nameB' via return statement.
	 String getnameB()
		{
			return nameB;
		}

}

mainClass

/**
 * 
 */
package GetterSetter;

/**
 * @author ashok.kumar
 *
 */
public class mainClass {

	public static void main(String[] args) {
		
		ClassA objA=new ClassA(10,"Rambo");
		
		System.out.println("Value of ClassA object");
		System.out.println(objA.roll + " " + objA.name);
		
		objA=new ClassA(20,"Ramesh");
		System.out.println(objA.roll + " " + objA.name);
		
		ClassB objB=new ClassB();
		objB.setrollB(20);
		objB.setnameB("Ajay");
		
		System.out.println("\nValue of ClassB object");
		objB.getrollB();                        // First method to read/access Class variable.
		System.out.println(objB.getnameB());   // Alternate method to read/access Class variable.
		
		objB.setrollB(30);
		objB.setnameB("Rajan");
		objB.getrollB();
		System.out.println(objB.getnameB());
		
		objB.setrollB(40);
		objB.setnameB("Sonu");
		objB.getrollB();
		System.out.println(objB.getnameB());
	}

}

Console Output
Value of ClassA object
10 Rambo
20 Ramesh

Value of ClassB object
20
Ajay
30
Rajan
40
Sonu

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