Example: Display Prime Numbers Between two Intervals
public class Prime {
public static void main(String[] args) {
int low = 20, high = 50;
while (low < high) {
boolean flag = false;
for(int i = 2; i <= low/2; ++i) {
// condition for nonprime number
if(low % i == 0) {
flag = true;
break;
}
}
if (!flag && low != 0 && low != 1)
System.out.print(low + " ");
++low;
}
}
}
Output
23 29 31 37 41 43 47
In this program, each number between low and high are tested for prime. The inner for loop checks whether the number is prime or not.
You can check: Java Program to Check Prime Number for more explanation.
The difference between checking a single prime number compared to an interval is, you need to reset the value of flag = false on each iteration of the while loop.
Note: If you check the interval from 0 to 10. Then, you need to exclude 0 and 1. As 0 and 1 are not prime numbers. The condition will be:
if (!flag && low != 0 && low != 1)