c++动态内存

  1 #include<iostream>
  2 #include<string.h>
  3 #include<stdlib.h>
  4 using namespace std;
  5 // error!
  6 void getPointer(char * pr, int num)
  7 {
  8
  9     pr = (char *)malloc(sizeof(char)*num);
10
11 }
12
13 //正确
14 char * getd(char * pr, int num)
15 {
16
17     pr = (char *)malloc(sizeof(char)*num);
18
19     return pr;
20 }
21 //正确
22 void getc(char ** pr, int num)
23 {
24    
25     *pr = (char *)malloc(sizeof(char)*num);
26
27 }
28
29
30 int main()
31 {      
32         char * str = NULL;
33         getc(&str,100);
34         strcpy(str,"hrl");
35         cout<<"str:"<<str<<endl;
36         return 0;
37
38 }