C申請內存函數

#include <iostream>
using namespace std;

//傳值調用
void GetMemory( char **p )
{
    *p = (char *) malloc( 100 );
}
//引用調用
void GetMemory_1(char *&p)
{
    p = (char *) malloc (100);
}

int main()
{
    char *str = NULL;
    char *str1 = NULL;
    GetMemory( &str );
    GetMemory_1( str1 );
    strcpy( str, "hello world" );
    strcpy( str1, "hello world1" );
    cout<<str<<endl;
    cout<<str1<<endl;
    free(str);
    free(str1);
    return 0;

}