java阶乘的实现（scanner使用练习）

public class test {
    public static void main(String[] args) {
        System.out.println("请输入计算x！的x值");
        Scanner scanner = new Scanner(System.in);
        int m = scanner.nextInt();
        int x = m;
        int sum = 1;
        if (m>0){
            while (m > 0) {
                sum = m *sum;
                m = --m;
            }
        System.out.println(x+"!="+sum);
        }
        else System.out.println("无法计算");
        scanner.close();
    }
}

缺点：输入非int类型数据报错
总结：

1.new一个Scanner
2.scanner.next()
3.关闭scanner