4.给定一个正整数m，统计m的位数，分别打印每一位数字，再按照逆序打印出各位数字。 要求：m定义为类的属性，需定义构造函数为m赋值；当m大于99999时，输出错误信息“the number is to...

package a;

public class ShuZi {
    
    int m;

    public int getM() {
        return m;
    }

    public void setM(int m) {
        this.m = m;
    }
    public void shu()
    {
        System.out.println("输入的数字是:"+m);
        if(m>99999)
        {
            System.out.println("The number is too large");
            
        }
        else if(m<0)
        {
            System.out.println("必须输入正整数");
        }
        else
        {
            System.out.println("m的位数为："+String.valueOf(m).length()+"位");
            System.out.print("逆序打印数字：");
            for(int i=String.valueOf(m).length()-1;i>=0;i--)
            {
                System.out.print(String.valueOf(m).substring(i,i+1));
            }
            
        }
    }
          public static void main(String[] args) {
              ShuZi shu=new ShuZi();
              shu.setM(3684);
              shu.shu();
    
}
}

m的值无限制时

package a;

public class ShuZi {
    
    String m;

    public String getM() {
        return m;
    }

    public void setM(String m) {
        this.m = m;
    }
    public void shu()
    {
        System.out.println("输入的数字是:"+m);    
         if(m.substring(0,1).equals("-"))
        {
             
            System.out.println("必须是正整数");
            
        }
        else
        {
            System.out.println("数字的位数为："+m.length()+"位");
            System.out.print("逆序打印数字：");
            for(int i=m.length()-1;i>=0;i--)
            {
                System.out.print(m.substring(i,i+1));
            }
            
        }
    }
          public static void main(String[] args) {
              ShuZi shu=new ShuZi();
              shu.setM("325340069646798572422365125");
              shu.shu();
    
}
}

转载于:https://www.cnblogs.com/wenwen123/p/5534508.html