我有一个让我头痛的家庭作业挑战。问题是：
构建一个使用字符串数组存储以下名称的程序：
*“佛罗里达”
*“俄勒冈”
*“加利福尼亚”
*“格鲁吉亚”
使用前面的字符串数组，编写自己的sort（）函数来显示＆gt;使用strcmp（）函数按字母顺序排列每个州的名称。
这是我的代码，它给了我一些问题：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
//function prototype
int sort(char *, char *);
int main()
{
char *strStates[] = {"Florida", "Oregon", "California", "Georgia"};
char *strSorted[] = {0};
int x;
printf("\nThe list of states before being sorted in alphabetical order: ");
for (x = 0; x < 4; x++)
{
printf("\n%s", strStates[x]);
}
sort(strStates[x], strSorted[x]);
printf("\nThe list of states sorted alphabetically are: ");
for (x = 0; x < 4; x++)
{
printf("\n%s", strStates[x]);
}
return 0;
}//end main
//function definition
int sort(char *string1, char *string2)
{
int x;
int y;
for (x = 0; x < 3; x++)
{
for (y = 1; y < 4; y++)
{
if ((strcmp(string1[x], string1[y])) > 0)
{
strcpy(string2, string1[x]);
strcpy(string1[x], string1[y]);
strcpy(string[y], string2);
}//end if
}//end inner for loop
}//end outer for loop
}//end sort()
编译时我遇到了一系列错误：
Chapter_8_Challenge_3.c:45:16: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'const char *'; take the address with & [-Wint-conversion]
if ((strcmp(string1[x], string1[y])) > 0)
^~~~~~~~~~
&
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/string.h:77:25: note: passing argument to parameter here
int strcmp(const char *, const char *);
^
Chapter_8_Challenge_3.c:45:28: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'const char *'; take the address with & [-Wint-conversion]
if ((strcmp(string1[x], string1[y])) > 0)
^~~~~~~~~~
&
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/string.h:77:39: note: passing argument to parameter here
int strcmp(const char *, const char *);
^
Chapter_8_Challenge_3.c:47:21: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'const char *'; take the address with & [-Wint-conversion]
strcpy(string2, string1[x]);
^~~~~~~~~~
&
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:33: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
Chapter_8_Challenge_3.c:48:12: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'const void *' [-Wint-conversion]
strcpy(string1[x], string1[y]);
^~~~~~~~~~
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:53: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_common.h:39:54: note: expanded from macro '__darwin_obsz'
#define __darwin_obsz(object) __builtin_object_size (object, _USE_FORTIFY_LEVEL > 1 ? 1 : 0)
^
Chapter_8_Challenge_3.c:48:12: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'char *'; take the address with & [-Wint-conversion]
strcpy(string1[x], string1[y]);
^~~~~~~~~~
&
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:27: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
Chapter_8_Challenge_3.c:48:24: warning: incompatible integer to pointer conversion passing 'char' to parameter of type 'const char *'; take the address with & [-Wint-conversion]
strcpy(string1[x], string1[y]);
^~~~~~~~~~
&
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:33: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
Chapter_8_Challenge_3.c:49:12: error: use of undeclared identifier 'string'; did you mean 'string1'?
strcpy(string[y], string2);
^~~~~~
string1
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:27: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
Chapter_8_Challenge_3.c:36:16: note: 'string1' declared here
int sort(char *string1, char *string2)
^
Chapter_8_Challenge_3.c:49:12: error: use of undeclared identifier 'string'
strcpy(string[y], string2);
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_string.h:83:53: note: expanded from macro 'strcpy'
__builtin___strcpy_chk (dest, src, __darwin_obsz (dest))
^
/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.11.sdk/usr/include/secure/_common.h:39:54: note: expanded from macro '__darwin_obsz'
#define __darwin_obsz(object) __builtin_object_size (object, _USE_FORTIFY_LEVEL > 1 ? 1 : 0)
^
6 warnings and 2 errors generated.
答案 0 :(得分：1)
1。在您的函数sort -
if((strcmp(string1[x],string1[y]))>0) //string1[x] is of type char-Wrong argument to strcmp
{
strcpy(string2, string1[x]); // same problem as aboce for all
strcpy(string1[x], string1[y]);
strcpy(string[y], string2);
}//end if
此string1已为char *，string1[x]的类型为char。所以这会调用未定义的行为。
2。在main -
for (x = 0; x < 4; x++)
{
printf("\n%s", strStates[x]);
}
sort(strStates[x], strSorted[x]);
也许您打算将char指针数组（strStates）作为第一个参数传递，并将（strSorted）作为第二个参数传递。那么sort中的上述问题也将得到解决。
3。最后，您的int sort()功能不会return任何内容，所以您再次获得 UB 。
注意 - 您收到的错误是因为将char传递给字符串函数。
答案 1 :(得分：0)
除了sort函数参数的错误之外，您还应该考虑使用strcpy。您不能将字符串文字复制到另一个字符串文字中，因为它们是只读的。
你真的需要复制字符串吗？您有输入字符串指针的数组。您只能在不触及实际字符串的情况下对这些指针进行排序。
你可以传递那个指针数组并对它们进行排序：
void sort(char *strStates[])
{
int x, y;
for (x = 0; x < 3; x++)
{
for (y = x + 1; y < 4; y++)
{
if ((strcmp(strStates[x], strStates[y])) > 0)
{
char *tmp = strStates[x];
strStates[x] = strStates[y];
strStates[y] = tmp;
}//end if
}//end inner for loop
}//end outer for loop
}//end sort()
可以将其称为sort(strStates)。
您还可以考虑将数组大小传递到该函数中，以避免幻数3和4：void sort(char *strStates[], int size)。
答案 2 :(得分：0)
您的sort函数收到2个字符串作为参数，因此if ((strcmp(string1[x], string1[y])) > 0)正在尝试将两个字符与strcmp进行比较。你的排序功能应该更像这样：
void sort(char **unsortedStrings){
int x;
int y;
for (x = 0; x < 3; x++)
{
for (y = x+1; y < 4; y++)
{
if ((strcmp(unsortedStrings[x], unsortedStrings[y])) > 0)
{
// There is no need to use strcpy here, just re-order the pointers
char *tmp = unsortedStrings[x];
unsortedStrings[x] = unsortedStrings[y];
unsortedStrings[y] = tmp;
}//end if
}//end inner for loop
}//end outer for loop
}//end sort()
此外，您的排序函数表示它应该返回一个int，但没有返回任何内容。您要么返回一些内容（如果一切正常则为return 1，或者如果失败则为return 0），或者您应将其声明为void