Methods (Function)

on

 Methods in Java

  • Introduction of method/funtion

Method is a process to perform specific Task

Example : 



  • methods:
  • electrician()
  • plumber()
  • builder()
  • painting()
  • wooden work()
Syntax : 

access_modifier return_type method_name() { 
             method body(code to perform the task)
 }

  1. method_name: This is the name of the method. It should follow Java naming conventions .
  2. Method body:  It contains the statements and logic to perform the desired task.
  3. return_type: This specifies the data type of the value that the method will return.
Methods
  • A method is a self-contained Block of statement that perform a specific task of some kind.
  • Every Java program has one or more methods in it.
method (call and definition):

public class manvikfun {
    public static void main(String[] args) {
        gym();//method call
        System.out.println("hi i am manvik");
    }
    static void gym(){//method defination
        System.out.println("i am in gym ");
    }
}

# Out put: 
   i am in gym 
   hi i am manvik

here, 
        We define two methods -main() and gym() and used gym word two time. Let us understand meaning of each .

First gym()
static void gym()//method defination
{
        System.out.println("i am in gym ");
    }
  1. This is method definition. 
Second gym()

gym();//method call

here,
        main() call gym() 
  
  • When we say that main() call the method gym() we mean that control passes to method gym() then method going to work , after the execution of method control return to main() which come to life again and begins executing its code at the exit point.
  • main() become a calling function.
  • gym() become the called method(function).

Call more then one method
  • Java can contain one or more classes each class can contain one or more methods.
  • execution always begins with main() function present in class that class is main class.
  • Class must contain main() because program execution always start with main() function.
  • sequence execution. 
public class manvikfun {
    public static void main(String[] args) {
        gym();//method call
        benchpress();//second call
        squats();//third call
        deadlift();//fourth call
        System.out.println("hi i am manvik");
    }
    static void gym(){//method defination
        System.out.println("i am in gym ");
    }
    static void benchpress(){//method defination
        System.out.println(" chest day ");
    }
    static void squats(){//method defination
        System.out.println("leg day");
    }
    static void deadlift(){//method defination
        System.out.println("back day");
    }
}
 
#Output
i am in gym 
chest day 
leg day
back day
hi i am manvik

One method call another method
Any method can call from any other method. Even main() can be called from other method.
public class manvikfun {
    public static void main(String[] args) {
        System.out.println("Before-START-");
        gym();//method call
        System.out.println("after-END-");
    }
    static void gym(){//method defination
        System.out.println("i am in gym-START-");
        benchpress();
        System.out.println("i am in gym-END-");
    }
    static void benchpress(){//method defination
        System.out.println(" chest day-START-");
        squats();
        System.out.println(" chest day-END-");
    }
    static void squats(){//method defination
        System.out.println("leg day-START-");
        deadlift();
        System.out.println(" leg day-END-");
    }
    static void deadlift(){//method defination
        System.out.println("back day");
    }
}
#Output 
Before-START-
i am in gym-START-
chest day-START-
leg day-START-
back day
leg day-END-
chest day-END-
i am in gym-END-
after-END-

Why use methods
  • Code Reusability
  • Abstraction
  • Modularity
  • Encapsulation
  • Code Readability
Pass by between methods(Parameters and Arguments): 
  • Information can be passed to methods as parameter. 
  • Parameters are specified after the method name, inside the parentheses
  • You can add as many parameters as you want
# Syntax:

access_modifier return_type method_name(parameters) { 
             method body(code to perform the task)
 }

# Example:
import java.util.Scanner;

public class para {
    public static void main(String[] args) {
        int add = 0;
        Scanner sc = new Scanner(System.in);
        System.out.println("enter any three numbers");
        System.out.println("a = ");
        int a = sc.nextInt();
        System.out.println("b = ");
        int b = sc.nextInt();
        System.out.println(" = ");
        int c = sc.nextInt();        

        System.out.println("Sum = "+sum(a, b, c ));
    }
    static int sum(int x, int y, int z ){
       
        return x + y + z;
    }
}

  • To pass the values of a, b, c to the method sum(), while making a call to the method sum() we have mentioned a, b, c in the parenthesis.
           sum(a, b, c);
  • In the sum() method these values get collected in three variables x, y, z.
         int sum( int x, int y, int z)
Note:

actual arguments ( a, b, c) also called just arguments

formal arguments (x , y , z) also called parameters


  • Quiz:
warning ⚠ - one time quiz 

Timer Quiz: Quiz Link
Non-Timer Quiz: non-timer Quiz Link

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