Methods In Java , Method calling in Java

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Methods in java
In java programming a method is a block of code that used to perform some specific task. In java method are basically used to write the business logic. In java we can create n number of instance methods and static method depends on the need .java methods improve the reusability of the program .
In java every method contain 3 components . 

• Method declaration 
• Method implementation 
• Method calling 

eg:
class Test
{  

int a=100;      

int b=200;     

public static void main(String[] args)

{  

Test t = new Test();     

t.add()  //Method Calling 

}

Void add()    // Method Declaration 

{

System.out.println(a);  //Method implementation 
System.out.println(b);  

}

}
Naming Convention for methods 

• Method Name should starts with lower cases letter .
• Every inner word should starts with upper cases letter.
• Methods should be a verb .
• Method name should in mix case.

Example 

eg : speedUp () , post ().

public class Employee  

{ 
void classTeacher () 

//business Logic  

} 

Method Declaration in java
Syntax-

public int addition (int x , int y)
{ 
   //Method body

}

here ,
public : Modifier name 
int : Return type 
addition : Method name
(int y , int y) : list of parameter

Types of method in java
There are 2 types of method in java 
1) Instance method (non static method )
2) Static method

Instance Method 
A method which don't contain any static keyword in its declaration those type of method is called as the non static method or instance method .

Syntax - Instance method

public class Employee  

{ 
void classTeacher ()  //instance Method 

//business Logic  

} 

Static method 
A method which have static keyword in its declaration those type of method is called as the static method .

Syntax - Static method

public class Employee  

{ 
static void classTeacher ()  //static Method 

//business Logic  

}

Calling method in java

1) Instance method Calling in java 
In java for the instance member memory is allocated when the object is created hence access the instance member by using reference variable (object name ).

class Test
{  

int a=100;      

int b=200;     

public static void main(String[] args)

{  

Test t = new Test();     

t.add()  //instance Method Calling 

}

Void add()     

{

System.out.println(a);   
System.out.println(b);  

}

}

2)Static method calling in java
In java for the static member memory allocated during the .class file loading, hence there are 3 approach to call static method in java .

Approach-1 Directly
Approach-2 By using class name 
Approach-3 By using reference variable 

class Test
{  
static int a=100;    
static int b=200;   

public static void main(String[] args)

{ 

Test.add();   //By Class name
add();         // Directly 
Test t =new Test();  
t.add();      // By reference variable 
}

static void add()
{
System.out.println(Test.a);

System.out.println(Test.b);  

}
}

Hope !!! The above lesson of java method helpful for you...

Thank You !
Sandeep Yadav

Tags : Method in java , java methods , methods calling in java , types of methods in java , how to declare the method in java , how to call methods in java 

Methods In Java , Method calling in Java