JAVA Basic Examples

KANERIA DHAVAL

1.Write Java program to check if a number is palindrome in Java?

public class palindrome

{

public static void main(String args[]){

int num,rev=0;

int mod,temp;

num=1001;

temp=num;

while(temp!=0){

mod=temp%10;

temp=temp/10;

rev=(rev*10)+mod;

}

if(num==rev)

System.out.println("number is palindrome");

else

System.out.println("number is not palindrome");

}

}

2. Write a program called SumAndAverage to produce the sum of 1, 2, 3, ..., to an upperbound (e.g., 100). Also compute and display the average. The output shall look like:The sum is 5050 The average is 50.5

public class SumAndAverage

{

public static void main(String args[])

{

int sum=0;

float avg;

for (int i=1;i<=100;i++){

sum=sum+i;

}

avg=sum/100;

System.out.println("the sum is "+sum);

System.out.println("the average is "+avg);

}

}

3. Write a program called Fibonacci to display the first 20 Fibonacci numbers F(n), where F(n)=F(nñ1)+F(nñ2) and F(1)=F(2)=1. Also compute their average. The output shall look like:

The first 20 Fibonacci numbers are:

1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765 The average is 885.5

public class Fibonacci

{

public static void main(String args[])

{

int f=0,sum=0;

int a=0,b=1;

float avg;

System.out.println("the first 20 fibonnaci numbers are ");

for(int i=0;i<20;i++){

f=a+b;

b=a;

a=f;

sum=sum+f;

System.out.print(f+"\t");

}

avg=sum/20;

System.out.println("\nthe average is "+avg);

}

}

4. Write a program called SquareBoard that displays the following n?n (n=5) pattern using two nested for-loops.

Expected output:

# # # # #

# # # # #

# # # # #

public class SquareBoard

{

public static void main(String args[])

{

int n=5;

for(int i=0;i<5;i++){

for(int j=0;j<5;j++)

System.out.print("# ");

System.out.println("");

}

}