topic:
Determine how many prime numbers are between 101-200 and output all prime numbers.
Program analysis:
The method of judging prime numbers: Divide a number from 2 to sqrt (this number). If it can be divided evenly, it means that the number is not a prime number, otherwise it is a prime number.
public class prime {
public static void main(String[] args) {
int count = 0;
for(int i=101; i<200; i+=2) {
boolean b = false;
for(int j=2; j<=Math.sqrt(i); j++){
if(i % j == 0) {
b = false;
break;
}else{
b = true;
}
}
if(b == true){
count ++;
System.out.println(i );
}
}
System.out.println( "素数个数是: " + count);
}
}