qsort - aid

Code:

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string *array;
//dynmically allocated

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Code:

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qsort ((void*)array, nNum, sizeof (*array), compare );

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Code:

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int compare(const void* string1, const void* string2)
{
  return stricmp ( (const char*)string1, (const char*)string2);
}

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it is not sorting data. Could someone help me :confused:

array is an array of std::string objects, not an array of char*. PROBABLY something like this (not compiled or tested):

Code:

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qsort ((void*)array, nNum, sizeof (string), compare );

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Code:

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int compare(const void* string1, const void* string2)
{
  std::string* s1 = (std::string*)string1;
  std::string* s2 = (std::string*)string2;
 
  return s1->compare(*s2);
}

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Just use std::sort instead of qsort.

Code:

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std::sort(array, array+size);

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You cannot cast a string to a const char*. If you want a const char* from a string, use the c_str() function.

The other posted solutions don't do case-insensitive string compares, so while you should use sort, you will still have to create your own comparison function that uses stricmp.

Wait, you want case-insensitive sorting, right? Give me a moment.

Quote:

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Originally Posted by Ancient Dragon

array is an array of std::string objects, not an array of char*. PROBABLY something like this (not compiled or tested):

Code:

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qsort ((void*)array, nNum, sizeof (string[0]), compare );

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Code:

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int compare(const void* string1, const void* string2)
{
  std::string* s1 = (std::string*)string1;
  std::string* s2 = (std::string*)string2;
 
  return s1->compare(*s2);
}

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it worked, thanks
but could you explain the return line please?

There you go:

Code:

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struct iless
{
  bool operator()(std::string &lhs, std::string &rhs) {
    return stricmp(lhs.c_str(), rhs.c_str()) < 0;
  }
};

std::sort(array, array+size, iless());

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Personally I'd do it differently, but this code is clearer.