Core Java Programs free java guide
Some Java programs which help lot of java beginners to understand the basic fundamentals in Java programming.
Program 1
//Find Maximum of 2 nos.
class Maxof2{
public static void main(String args[]){
//taking value as command line argument.
//Converting String format to Integer value
int i = Integer.parseInt(args[0]);
int j = Integer.parseInt(args[1]);
if(i > j)
System.out.println(i+" is greater than "+j);
else
System.out.println(j+" is greater than "+i);
}
}
Program 2
//Find Minimum of 2 nos. using conditional operator
class Minof2{
public static void main(String args[]){
//taking value as command line argument.
//Converting String format to Integer value
int i = Integer.parseInt(args[0]);
int j = Integer.parseInt(args[1]);
int result = (i<j)?i:j;
System.out.println(result+" is a minimum value");
}
}
Program 3
/* Write a program that will read a float type value from the keyboard and print the following output.
->Small Integer not less than the number.
->Given Number.
->Largest Integer not greater than the number.
*/
class ValueFormat{
public static void main(String args[]){
double i = 34.32; //given number
System.out.println("Small Integer not greater than the number : "+Math.ceil(i));
System.out.println("Given Number : "+i);
System.out.println("Largest Integer not greater than the number : "+Math.floor(i));
}
Program 4
/*Write a program to generate 5 Random nos. between 1 to 100, and it
should not follow with decimal point.
*/
class RandomDemo{
public static void main(String args[]){
for(int i=1;i<=5;i++){
System.out.println((int)(Math.random()*100));
}
}
}
Program 5
/* Write a program to display a greet message according to
Marks obtained by student.
*/
class SwitchDemo{
public static void main(String args[]){
int marks = Integer.parseInt(args[0]); //take marks as command line argument.
switch(marks/10){
case 10:
case 9:
case 8:
System.out.println("Excellent");
break;
case 7:
System.out.println("Very Good");
break;
case 6:
System.out.println("Good");
break;
case 5:
System.out.println("Work Hard");
break;
case 4:
System.out.println("Poor");
break;
case 3:
case 2:
case 1:
case 0:
System.out.println("Very Poor");
break;
default:
System.out.println("Invalid value Entered");
}
}
}
Program 6
/*Write a program to find SUM AND PRODUCT of a given Digit. */
class Sum_Product_ofDigit{
public static void main(String args[]){
int num = Integer.parseInt(args[0]); //taking value as command line argument.
int temp = num,result=0;
//Logic for sum of digit
while(temp>0){
result = result + temp;
temp--;
}
System.out.println("Sum of Digit for "+num+" is : "+result);
//Logic for product of digit
temp = num;
result = 1;
while(temp > 0){
result = result * temp;
temp--;
}
System.out.println("Product of Digit for "+num+" is : "+result);
}
}
Program 7
/*Write a program to Find Factorial of Given no. */
class Factorial{
public static void main(String args[]){
int num = Integer.parseInt(args[0]); //take argument as command line
int result = 1;
while(num>0){
result = result * num;
num--;
}
System.out.println("Factorial of Given no. is : "+result);
}
}
Program 8
/*Write a program to Reverse a given no. */
class Reverse{
public static void main(String args[]){
int num = Integer.parseInt(args[0]); //take argument as command line
int remainder, result=0;
while(num>0){
remainder = num%10;
result = result * 10 + remainder;
num = num/10;
}
System.out.println("Reverse number is : "+result);
}
}
Program 9
/*Write a program to find Fibonacci series of a given no.
Example :
Input - 8
Output - 1 1 2 3 5 8 13 21
*/
class Fibonacci{
public static void main(String args[]){
int num = Integer.parseInt(args[0]); //taking no. as command line argument.
System.out.println("*****Fibonacci Series*****");
int f1, f2=0, f3=1;
for(int i=1;i<=num;i++){
System.out.print(" "+f3+" ");
f1 = f2;
f2 = f3;
f3 = f1 + f2;
}
}
}
Program 10
/* Write a program to find sum of all integers greater than 100 and
less than 200 that are divisible by 7 */
class SumOfDigit{
public static void main(String args[]){
int result=0;
for(int i=100;i<=200;i++){
if(i%7==0)
result+=i;
}
System.out.println("Output of Program is : "+result);
}
}