java反向输入整数的位数可以采用取余判断的方式:
import java.util.Scanner;
public class Dd {
public static void main(String[] args){
Scanner in=new Scanner(System.in);
int n=in.nextInt();
int sum=0;
int i=1;
while(n>0){//当余数不为0的时候,继续操作
int d=n%10;
sum=sum*10+d;
n=n/10;
}
System.out.println(sum);
}
}
例如:输入123 n = 123;
壹. 123 > 0,d = 123%10 = 3,sum = 0 * 10 + 3 = 3,n = 123 % 10 = 12;
贰. 12 > 0,d = 12 %10 = 2,sum = 3 * 10 + 2 = 32,n = 12 % 10 = 1;
叁. 1 > 0,d = 1 %10 = 1,sum = 32 * 10 + 1 = 321,n = 1 % 10 = 0;