为什么我的程序在Dev c++上能运行，在VS 2019上不能

#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 name?\n");
    scanf("%s", name);
    printf("%s,what's your weught in pounds?\n", name);
    scanf("%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("and we have %d bytes to store it.\n", size);

    return 0;
}

在VS 2019上 scanf 我改成了 scanf_s

vs2019检查严格，注意以下几点：
1.变量在使用前必须初始化
2.scanf改为scanf_s
代码修改如下：

#include<stdio.h>
#include<string.h>
#define DENSITY (float)62.4
int main() 
{
    float weight = 0, volume = 0;
    int size = 0, letters = 0;
    char name[40] = {0};
    printf("Hi!What's your first name?\n");
    scanf_s("%s",name,39);
    printf("%s,what's your weught 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("and we have %d bytes to store it.\n", size);
    return 0;
}

你可以用#pragma warning(disable:4996)
来防止报错。
vs2019认为scanf安全性低,容易内存溢出,所以要加字符串长度。