getMemory（）-传递动态内存

void getMemory(char *p)
{
p=(char *)malloc(100);
}

char * getMemory(char *p)
{
char ch[]="hello world";
return ch;
}

char * getMemory(char **p)
{
*p=(char*)malloc(100);
return *p;
}

int main()
{
char *str=NULL;
// getMemory(str);
getMemory(&str);

if(str!=NULL)
cout<<"get Memory success"<<endl;
}