求阶乘、质数

public class A {

	public static void main(String[] args) {

	}

	// 求质数 100以内的
	public static void zhishu() {
		for (int j = 1; j < 100; j++) {
			int i = 0;
			for (int j2 = 1; j2 <= j; j2++) {
				if (j % j2 == 0) {
					i++;
				}
			}
			if (i == 2) {
				System.out.println(j + ",");
			}
		}
	}

	// 求阶乘
	public void jiecheng() {
		int a = 3;
		int b = 1;
		/*
		 * for (a = 3; a > 0; a--) { b = b * a; }
		 */
		while (a > 0) {
			b = b * a;
			a--;
		}
		System.out.println(b);
		A.zhishu();
	}
}