JAVA program to print all prime numbers between two user given numbers.
import java.io.*;
public class MyMain {
public static void main(String[] args) {
// TODO Auto-generated method stub
InputStreamReader istream = new InputStreamReader(System.in) ;
BufferedReader read = new BufferedReader(istream) ;
System.out.print("Enter the first number: ");
int num1=0, num2=0;
try{
num1=Integer.parseInt(read.readLine() );
System.out.print("Enter the second number: ");
num2=Integer.parseInt(read.readLine() );
if(num1>=num2){ //Checking for valid range
System.out.println("The first number should must be less than the second number.");
}
else{
for(int i=num1;i<=num2;i++){
int count = 0; //Setting a counter
for(int j=1;j<=i;j++){
if(i%j==0) count++;
}
if(count == 2)
System.out.println(i+ " is a prime number.");
else
System.out.println(i+ " is a non-prime number.");
}
}
} catch(Exception Number){
System.out.println("Invalid Number!");
}
}
}
Output:
Enter the first number: 12
Enter the second number: 23
12 is a non-prime number.
13 is a prime number.
14 is a non-prime number.
15 is a non-prime number.
16 is a non-prime number.
17 is a prime number.
18 is a non-prime number.
19 is a prime number.
20 is a non-prime number.
21 is a non-prime number.
22 is a non-prime number.
23 is a prime number.
Write a JAVA program to check whether a number is prime or not.
import java.io.*;
public class PrimeCheck {
public static void main(String[] args) {
// TODO Auto-generated method stub
InputStreamReader istream = new InputStreamReader(System.in) ;
BufferedReader read = new BufferedReader(istream) ;
System.out.print("Enter the number: ");
int num=0;
try{
num=Integer.parseInt(read.readLine() );
int count = 0;
for(int i=1;i<=num;i++){
if(num%i == 0) count++;
}
if(count == 2) {
System.out.println("The number "+num+" is prime.");
}
else{
System.out.println("The number "+num+" is not prime.");
}
} catch(Exception Number){
System.out.println("Invalid Number!");
}
}
}
