memcpy( )的使用以及迭代器的使用

memcpy() -- 拷贝内存内容

相关函数: bcopy(), memccpy(), memmove(), strcpy(), strncpy()
表头文件: #include <string.h>
定义函数: void *memcpy(void *dest, const void *src, size_t n)
函数说明: memcpy()用来拷贝src所指的内存内容前n个字节到dest所指的内存地址上。与strcpy()不同的是,memcpy()会完整的复制n个字节,不会因为遇到字符串结束'\0'而结束
返回值:   返回指向dest的指针
附加说明: 指针src和dest所指的内存区域不可重叠

   1:  #include <string.h>

   2:  #include <stdio.h>

   3:   

   4:  int main()

   5:  {

   6:      char a[30] = "string (a)";

   7:      char b[30] = "hi\0zengxiaolong";

   8:      int i;

   9:   

  10:      strcpy(a, b);             //a[30] = "hi\0ing (a)"

  11:      printf("strcpy():");

  12:      for(i = 0; i < 30; i++)

  13:          printf("%c", a[i]);   //hi ing (a)

  14:   

  15:   

  16:      memcpy(a, b, 30);         //a[30] = "hi\0zengxiaolong"

  17:      printf("\nmemcpy():");

  18:      for(i = 0; i < 30; i++)

  19:          printf("%c", a[i]);   //hi zengxiaolong

  20:      printf("\n i = %d\n", i); //30

  21:   

  22:  }

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iterator是C++标准库（STL）中的迭代器~~~

比如你建一个链表（要记得#include <list>

#include <iostream>）

list<char> A;

再list<char>::iterator it，这样，就可以对链表进行遍历了~

其实，你可以把它理解成类似指针的东西~当然，只是用处差不多，使用方式和声明方式可是完全不同的喔~~

PS：再给你一个简单的小

程序段，可以说明iterator的用处~

   1:  #include <list> 

   2:  #include <iostream> 

   3:  using namespace std;

   4:   

   5:  void main(void) 

   6:  { 

   7:  int a[]={1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; 

   8:  list<int> name(a,a+10); 

   9:   

  10:  list<int>::iterator it; 

  11:  for (it = name.begin(); it != name.end(); it++) 

  12:  { 

  13:  cout << *it << endl;   //就是可以指向容器中元素的东西，就好像指针那样，但是它不是指针。

  14:  } 

  15:  } 

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