Basic java programs
- Write a java program to print hello world
public class Simple
{
public static void main(String args[])
{
System.out.println("Hello World");
}
}
OUTPUT:
Hello Java
Hello World
- Write a java program to add two number.
public class Simple{
public static void main(String[] args){
int a=10;
int b=10;
int c=a+b;
System.out.println(c);
}
}
OUTPUT:
20
20
- Write a java program for widening.
public class Simple
{
public static void main(String[] args)
{
int a=10;
float f=a;
System.out.println(a);
System.out.println(f);
}
}
Output:
10
10.0
10
10.0
- Write a java program for Narrowing (Typecasting).
public class Simple
{
public static void main(String[] args)
{
float f=10.5f;
//int a=f;//Compile time error
int a=(int)f;
System.out.println(f);
System.out.println(a);
}
}
Output:
10.5
10.5
10
- Write a java program using if statement.
public class Student
{
public static void main(String[] args)
{
int x = 10;
int y = 12;
if(x+y > 20)
{
System.out.println("x + y is greater than 20");
}
}
}
Output:
x + y is greater than 20
- Write a java program using if-else statement.
public class Student
{
public static void main(String[] args)
{
int x = 10;
int y = 12;
if(x+y < 10)
{
System.out.println("x + y is less than 10");
} else {
System.out.println("x + y is greater than 20");
}
}
}
Output:
x + y is greater than 20
- Write a java program using if-else-if statement.
public class Student
{
public static void main(String[] args)
{
String city = "Delhi";
if(city == "Meerut")
{
System.out.println("city is meerut");
}
else if (city == "Noida")
{
System.out.println("city is noida");
}
else if(city == "Agra")
{
System.out.println("city is agra");
}
else
{
System.out.println(city);
}
}
}
Output:
Delhi
- Write a java program for Nested if-statement.
public class Student
{
public static void main(String[] args)
{
String address = "Delhi, India";
if(address.endsWith("India"))
{
if(address.contains("Meerut"))
{
System.out.println("Your city is Meerut");
}
else if(address.contains("Noida"))
{
System.out.println("Your city is Noida");
}
else
{
System.out.println(address.split(",")[0]);
}
}
else
{
System.out.println("You are not living in India");
}
}
}
Output:
Delhi
- Write a java program using switch statement.
public class Student implements Cloneable
{
public static void main(String[] args) {
int num = 2;
switch (num){
case 0:
System.out.println("number is 0");
break;
case 1:
System.out.println("number is 1");
break;
default:
System.out.println(num);
}
}
}
Output:
2
- Write a java program using for loop.
public class Calculattion
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
int sum = 0;
for(int j = 1; j<=10; j++)
{
sum = sum + j;
}
System.out.println("The sum of first 10 natural numbers is " + sum);
}
}
Output:
The sum of first 10 natural numbers is 55
- Write a java program using for-each loop.
public class Calculation
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
String[] names = {"Java","C","C++","Python","JavaScript"
};
System.out.println("Printing the content of the array names:\n");
for(String name:names)
{
System.out.println(name);
}
}
}
Output:
Printing the content of the array names:
Java
C
C++
Python
Printing the content of the array names:
Java
C
C++
Python
Javascript
12.Write a java program using while loop.
public class Calculation
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
int i = 0;
System.out.println("Printing the list of first 10 even numbers \n");
while(i<=10)
{
System.out.println(i);
i = i + 2;
}
}
}
Output:
Printing the list of first 10 even numbers
0
2
4
6
8
Printing the list of first 10 even numbers
0
2
4
6
8
10
- Write a java program using do-while loop.
public class Calculation
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
int i = 0;
System.out.println("Printing the list of first 10 even numbers \n");
do {
System.out.println(i);
i = i + 2;
}while(i<=10);
}
}
Output:
Printing the list of first 10 even numbers
0
2
4
6
8
Printing the list of first 10 even numbers
0
2
4
6
8
10
- Write a java program using break statement.
public class BreakExample
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
for(int i = 0; i<= 10; i++)
{
System.out.println(i);
if(i==6) {
break;
}
}
}
}
Output:
0
1
2
3
4
5
0
1
2
3
4
5
6
- Write a java program using continue statement.
public class ContinueExample
{
public static void main(String[] args)
{
// TODO Auto-generated method stub
for(int i = 0; i<= 2; i++)
{
for (int j = i; j<=5; j++)
{
if(j == 4)
{
continue;
}
System.out.println(j);
}
}
}
}
Output:2
3
0
1
2
3
5
1
2
3
5
2
3
5
