判断整数的位数

 1 #include<stdio.h>
 2 
 3 int main(void)
 4 {
 5     int x;
 6     int n = 0;
 7     
 8     scanf_s("%d", &x);
 9 
10     x = x / 10;
11     n++;
12 
13     while (x > 0)
14     {
15         x = x / 10;
16         n++;
17     }
18 
19     printf("%d\n", n);
20 
21     return 0;
22 }

 1 #include<stdio.h>
 2 
 3 int main(void)
 4 {
 5     int x;
 6     int n = 0;
 7 
 8     scanf_s("%d", &x);
 9 
10     do
11     {
12         x = x / 10;
13         n++;
14     } while (x > 0);
15 
16     printf("%d\n", n);
17 
18     return 0;
19 }

 1 #include<stdio.h>
 2 
 3 int main(void)
 4 {
 5     int x, y =1;
 6     int n = 0;
 7 
 8     scanf_s("%d", &x);
 9 
10     do
11     {
12         x = x / 10;
13         n++;
14     } while (x != 0);    //不等于0，继续循环
15 
16     printf("%d\n", n);
17 
18     return 0;
19 }