Java Programs

First java program:

class hello

{

public static void main(String [] args)

    {

       System.out.println("hello ATMECE");

    }

}

OUTPUT:

hello ATMECE

Adding two numbers

Example 1:

class add

{

public static void main(String []args)

   {

        int a=100,b=200,c;

        c=a+b;

        System.out.println(c);

   }

}

OUTPUT:

300

Example 2:

class add

{

public static void main(String []args)

  {

      int a=100,b=200,c;

       c=a+b;

       System.out.println(a+"+"+b+"="+c);

   }

}

OUTPUT:

100+200=300

Example 3:

Reading two numbers from keyboard and adding them:

import java.util.Scanner;

class add1

{

public static void main(String [] args)

 {

    int a,b,c;

    Scanner s=new Scanner(System.in);

    System.out.println("Enter a and b values:");

    a=s.nextInt();

    b=s.nextInt();

   

 c=a+b;

    System.out.println(a+"+"+b+"="+c);

  }

}

OUTPUT:

Enter a and b values:

871

232

871+232=1103

Reading name and age values from keyboard:

import java.util.Scanner;

class name

{

public static void main(String [] args)

  {

     String name;

     int age;

     Scanner s=new Scanner(System.in);

     System.out.println("Enter your name:");

     name=s.nextLine();

     System.out.println("Enter your age:");

     age=s.nextInt();

     System.out.println("HAI "+name+", you are "+age+" years old");

  }

}

OUTPUT:

Enter your name:

kumar

Enter your age:

30

HAI kumar, you are 30 years old

Array in java:

import java.util.Scanner;

class array

{

public static void main(String [] args)

  {

     Scanner s=new Scanner(System.in);

     System.out.println("enter array size:");

     int n=s.nextInt();

     int a[] =new int[n];

     System.out.println("enter array elements:");

     for(int i=0;i<n;i++)

        a[i]=s.nextInt();

    System.out.println("enter array elements:");

       for(int i=0;i<n;i++)

           System.out.println(a[i]);

   }

}

OUTPUT:

enter array size:

5

enter array elements:

11

22

33

44

55

entered array elements:

11

22

33

44

55

Array of STRINGS:

import java.util.Scanner;

class array

{

public static void main(String [] args)

  {

    Scanner s=new Scanner(System.in);

    System.out.println("enter array size:");

    int n=s.nextInt();

    s.nextLine();

    

  String a[] =new String[n];

     System.out.println("enter array elements:");

     for(int i=0;i<n;i++)

     a[i]=s.nextLine();

     

  System.out.println("enter array elements:");

     for(int i=0;i<n;i++)

     System.out.println(a[i]);

  }

}

OUTPUT:

enter array size:

5

enter array elements:

atmece

mysore

computer science

ananda

kumar

entered array elements:

atmece

mysore

computer science

ananda

kumar

Object creation and Default Constructor:

class constru

{

int a;

float b;

String c;

double d;

public constru()

{

   a=100;

   b=89;

   c="atmece cse";

   d=34.98877666665555566555;

}

public static void main(String [] args)

  {

    constru c=new constru();

    System.out.println("a="+c.a);

    System.out.println("b="+c.b);

    System.out.println("c="+c.c);

    System.out.println("d="+c.d);

  }

}

OUTPUT:

a=100

b=89.0

c=atmece cse

d=34.98877666665555

User defined function:

class fun

{

int a;

float b;

String c;

double d;

public fun()

  {

     a=100;

     b=89;

     c="atmece cse";

     d=34.98877666665555566555;

  }

public void display()

  {

     System.out.println("a="+a);

     System.out.println("b="+b);

     System.out.println("c="+c);

     System.out.println("d="+d);

  }

public static void main(String [] args)

  {

     fun c=new fun();

     c.display();

  }

}

OUTPUT:

a=100;

b=89;

c="atmece cse";

d=34.98877666665555566555;

Parameterized Constructor:

class fuct

{

int a;

float b;

String c;

double d;

public fuct(int x,float y,String s,double z)

  {

     a=x;

       b=y;

       c=s;

       d=z;

  }

public void display()

  {

     System.out.println("a="+a);

     System.out.println("b="+b);

     System.out.println("c="+c);

     System.out.println("d="+d);

  }

public static void main(String [] args)

  {

    fuct c=new fuct(899,33,"atmece mys",543.4543);

    c.display();

  }

}

OUTPUT:

a=899

b=33.0

c=atmece mys

d=543.4543

Program to show Array of objects:

import java.util.Scanner;

class emplo

{

  String name;

  int usn;

public emplo()

  {

    Scanner s=new Scanner(System.in);

 System.out.println("Enter student name:");

   name=s.nextLine();

    

 System.out.println("Enter student usn:");

  usn=s.nextInt();

  }

public void printinfo()

  {

     System.out.println(name+"\t"+usn);

  }

public static void main(String [] args)

  {

     Scanner s=new Scanner(System.in);

     System.out.println("Enter total number of students:");

     int n=s.nextInt();

  emplo e[]=new emplo[n];

     System.out.println("Enter student details:");

     for(int i=0;i<n;i++)

           e[i]=new emplo();

  System.out.println("entered details are:");

     System.out.println("--------------------");

     System.out.println("Name\tUSN");

     System.out.println("--------------------");

       for(int i=0;i<n;i++)

            e[i].printinfo();

     System.out.println("--------------------");

  }

}

OUTPUT:

Enter total number of students:

3

Enter student details:

Enter student name:

raghav

Enter student usn:

111

Enter student name:

prabhu

Enter student usn:

222

Enter student name:

yashas

Enter student usn:

333

entered details are:

--------------------

Name USN

--------------------

raghav 111

prabhu 222

yashas 333

--------------------