求素数

public class PrimeDemo {

	static int primeCount = 0;
	
	public static void main(String[] args){
		int num = 100;
		System.out.println(num + "以内的素数:");
		for(int i=3;i<=num;i++){
		int tempCount = 0;
		if(!isPrime(i,tempCount)){
			++ primeCount;
			System.out.print(i + "\t");
			}
		 tempCount = 0;
		}
		System.out.println("\n100以内的素数总共有:" + primeCount + "个");
	}
	
	private static boolean isPrime(int a,int tempCount){
		int sqrt = (int) Math.sqrt(a);
		// for(int k=2;k<=a-1;k++){
		for(int k=2;k<=sqrt;k++){
			if(a%k == 0)
				++ tempCount;
		}
		return (tempCount == 0) ? false : true;
	}
}