第4章例4-3

#include<stdio.h>
int main(void)
{
	int count,number;

	count=0;
	printf("Enter a number:");
	scanf("%d",&number);
	if(number<0)number=-number;
	do{
		number=number/10;
		count++;
	}while(number!=0);
	printf("It contains %d digits.\n",count);

	return 0;
}