以下是必需的程序。
public class Tester { public static void main(String args[]) { int i, m = 0, flag = 0; int n = 41;// it is the number to be checked m = n / 2; if (n == 0 || n == 1) { System.out.println(n + " not a prime number"); } else { for (i = 2; i <= m; i++) { if (n % i == 0) { System.out.println(n + " not a prime number"); flag = 1; break; } } if (flag == 0) { System.out.println(n + " is a prime number"); } } } }
输出结果
41 is a prime number.