Question

c语言程序运行错误？

#include<stdio.h>
#include<string.h>
#define DENSITY 62.4;
int main()
{
float weight, volume;
int size, letters;
char name[40];

printf("hi!what's your first nane?\n");
scanf_s("%s", name);
printf("%s.what's your weight in pounds?\n", name);
scanf_s("%f", &weight);
size = sizeof name;
letters = strlen(name);
volume = weight / DENSITY;
printf("well,%s,your volume is %2.2f cubic feet.\n", name, volume);
printf("also,your first name has %d letters,\n", letters);
printf("and we have %d bytes to store ie.\n", size);
return 0;
}在vs2017运行这个程序以后，输入name以后程序就终止了。请问哪里有错呢？

Answer 1

scanf_s("%s", name, 39);
这是最主要的问题，顺便把宏也改成如下形式：
#define DENSITY 62.4
即去掉分号

追问

谢谢。为什么要加个39呢？书上就没有加啊

追答

因为你的name定义的长度为40，所以这里设置读取的最大长度为39，留一个放结束符