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！");
}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！");
}
public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 1;
for(int i = 10;num/i>=1;i*=10)
count++;
System.out.println("它是个"+count+"位的数！");
}
}
可以的吧
因为这里不确定循环的次数