判断一个整数是否为质数/素数，最主要的就是要知道什么叫质数/素数；
质数/素数是指在大于1的数中能被自身和一整除的整数。
public boolean Member(int a) {int count = 0;for (int i = 1;i<=a;i++) {if (a%i==0) {count++;}}if (count==2) {System.out.println(a+"为质数");return true;}else {System.out.println(a+"不为质数");return false;}}public static void main(String[] args) {Prime prime =new Prime();Scanner scanner = new Scanner(System.in);System.out.println("请输入一个整数:");int c = scanner.nextInt();System.out.println(prime.Member(c));}
输出给定范围中的质数：
public static void main(String[] args) {// TODO 判断质数Scanner scan = new Scanner(System.in);System.out.println("输入开始值:");int s = scan.nextInt();System.out.println("输入结束值:");int e = scan.nextInt();printPrime(s,e);scan.close();}public static boolean isPrime(int n) {//此方法用来判断质数boolean isPrime = true;for (int i = 2; i < n; i++) {if(n%i ==0) {isPrime = false;break;}}return isPrime;}public static void printPrime(int start,int end) {//用来输出范围中的质数for(int i =start;i<=end;i++) {//boolean b = ZhishuDemo.isPrime(i);if(b) {System.out.print(i+",");continue;}}
