The C language implements a level two pointer representing a string array

Header file:

#include <stdlib.h>#include<stdio.h>#include<string.h>

Function Prototypes:

Char* * Createbuff (Char**buff,intArraylength,intCharlength);//Create a level two pointervoidInitdemo (Char**buff,intArraylength);//initializing a level two pointervoidDestorybuff (Char**buff,intArraylength);//destroying level two pointersvoidPrintbuff (Char* * Buff,intArraylength);//traverse level Two pointersvoidSortbuffarray (Char* * Buff,intArraylength);//Sort

Implementation functions:

1 Char* * Createbuff (Char**buff,intArraylength,intcharlength) {2 3     inti;4     5Buff = (Char**)malloc(sizeof(Char*) *arraylength); Allocate space to *buff, the buff points to its first address6     7      for(i =0; i < arraylength; ++i) {8 9Buff[i] = (Char*)malloc(sizeof(Char) *charlength); *buff[i] Allocate space, Buff[i] point to its first addressTen  One     } A  -     returnBuff; - } the  - voidInitdemo (Char**buff,intarraylength) { -  -     inti; +  -      for(i =0; i < arraylength; ++i) { +  Asprintf (Buff[i],"%d%d%d", i +1, i +1, i +1); at  -     } - } -  - voidDestorybuff (Char**buff,intarraylength) { -  in     inti; -      to      for(i =0; i < arraylength; ++i) { +  -         if(Buff[i]! =NULL) { the              *              Free(Buff[i]);  $ Panax NotoginsengBuff[i] =NULL; -  the         } +  A     } the  +     if(Buff! =NULL) { -  $          Free(buff); $  -Buff =NULL; -  the     } - }Wuyi  the  -  Wu voidPrintbuff (Char* * Buff,intarraylength) { -  About     inti; $  -      for(i =0; i < arraylength; ++i) { -printf"%s\n", Buff[i]); -     } A } +  the voidSortbuffarray (Char* * Buff,intarraylength) { -  $     intI, J; the  the     Char*temp =NULL; the  the      for(i =0; i < arraylength; ++i) { -  in          for(j = i +1; J < Arraylength; ++j) { the  the             if(strcmp (Buff[j], buff[i]) >0){ About  thetemp =Buff[i]; the  theBuff[i] =Buff[j]; +  -BUFF[J] =temp; the Bayi             } the  the         } -  -     } the  the}

Test:

voidMain () {intArraylength =5, Charlength = -; Char**buff =NULL; Buff=createbuff (Buff, arraylength, charlength);    Initdemo (buff, arraylength); printf ("sort before \ n");    Printbuff (buff, arraylength);    Sortbuffarray (buff, arraylength); printf ("sort after \ n");    PrintArray (buff, arraylength);    Destorybuff (buff, arraylength); System ("Pause");}

Attention:

A char **buff variable cannot be passed as an argument to a formal parameter in the Createbuff function, so that the end of the Createbuff function call frees the parameter buff, so it can only be returned as a return value or, a three-level pointer is defined in the function, and the address of the buff is passed in when called.

The C language implements a level two pointer representing a string array