#include<iostream>
using namespace std;
#include<string>
//Define a structure
void getMem(char *ptr)
{
	ptr = (char*)malloc(sizeof(char)*100);
    if(nullptr == ptr)
    {
        cout<<"getMem ptr is nullptr"<<endl;
        return;
    }
    strcpy_s(ptr, 9, "abcd");
    cout << "getMem ptr:" << ptr<< endl;
}
int main(void)
{
	char* ptr = nullptr;
	getMem(ptr);
    if (nullptr == ptr)
    {
        cout << "main ptr is nullptr";
    }
    else
    {
        cout << "main ptr:" << ptr << endl;
    }

    system("pause");
    return 0;
}
/*
getMem ptr:abcd
main ptr is nullptr请按任意键继续. . .
*/