Scanf_s的一些想法

字符，字符串需要在scanf_s的第三项的输入能输入的最大字符数

#include<stdio.h>
#include<string.h>
#define DENSITY 62.4	//人体密度
int main()
{
	float weight;
	double volume;
	int size;
	unsigned long long int length;
	char name[10];
	name[9] = 0;
	
	printf("what's your first name?\n");
	scanf_s("%s", name,10);
	printf("%s ,what's your weight in pounds?\n", name);
	scanf_s("%f", &weight);
	size = sizeof(name);
	volume = weight/DENSITY ;
	length = strlen(name);
	printf("well,%s,your volume is %2.2f cubic feet.\n", name, volume);
	printf("Your first name has %llu letters.\n",length);
	printf("and we have %d bytes to store it .\n", size);

	return 0;
}

其中strlen的返回值是size_t类型，无符号数的整数型