看不懂啊，数学的逻辑思维太差了
public static void main(String[] args){ int num = 999; int count = 0; if(num >= 0 && num <= 999999999){while (num !=0 ) { count++; num/=10; } System.out.println("它是个"+ count + "位的数!"); } else { System.out.println("输入有误"); } } } 有谁看得懂的？告诉我一声
