wxArrayString Class Reference

#include <wx/arrstr.h>

Inheritance diagram for wxArrayString:

Detailed Description

wxArrayString is an efficient container for storing wxString objects.

It has the same features as all wxArray classes, i.e. it dynamically expands when new items are added to it (so it is as easy to use as a linked list), but the access time to the elements is constant, instead of being linear in number of elements as in the case of linked lists. It is also very size efficient and doesn't take more space than a C array wxString[] type (wxArrayString uses its knowledge of internals of wxString class to achieve this).

This class is used in the same way as other dynamic arrays(), except that no WX_DEFINE_ARRAY declaration is needed for it. When a string is added or inserted in the array, a copy of the string is created, so the original string may be safely deleted (e.g. if it was a wxChar * pointer the memory it was using can be freed immediately after this). In general, there is no need to worry about string memory deallocation when using this class - it will always free the memory it uses itself.

The references returned by wxArrayString::Item, wxArrayString::Last or wxArrayString::operator[] are not constant, so the array elements may be modified in place like this:

array.Last().MakeUpper();

Note

none of the methods of wxArrayString is virtual including its destructor, so this class should not be used as a base class.

Although this is not true strictly speaking, this class may be considered as a specialization of wxArray class for the wxString member data: it is not implemented like this, but it does have all of the wxArray functions.

It also has the full set of std::vector<wxString> compatible methods, including nested iterator and const_iterator classes which should be used in the new code for forward compatibility with the future wxWidgets versions.

Library:  wxBase

Category:  Containers

See Also

wxArray<T>, wxString, wxString Overview

Public Types
typedef int(*	CompareFunction )(const wxString &first, const wxString &second)
	The function type used with wxArrayString::Sort().

Public Member Functions
	wxArrayString ()
	Default constructor.
	wxArrayString (const wxArrayString &array)
	Copy constructor.
	wxArrayString (size_t sz, const wxString *arr)
	Constructor from a wxString array.
	~wxArrayString ()
	Destructor frees memory occupied by the array strings.
size_t	Add (const wxString &str, size_t copies=1)
	Appends the given number of copies of the new item str to the array and returns the index of the first new item in the array.
void	Alloc (size_t nCount)
	Preallocates enough memory to store nCount items.
void	Clear ()
	Clears the array contents and frees memory.
void	Empty ()
	Empties the array: after a call to this function GetCount() will return 0.
size_t	GetCount () const
	Returns the number of items in the array.
int	Index (const wxString &sz, bool bCase=true, bool bFromEnd=false) const
	Search the element in the array, starting from the beginning if bFromEnd is false or from end otherwise.
void	Insert (wxString lItem, size_t nIndex, size_t copies=1)
	Insert the given number of copies of the new element in the array before the position nIndex.
bool	IsEmpty () const
	Returns true if the array is empty, false otherwise.
void	Remove (const wxString &sz)
	Removes the first item matching this value.
void	RemoveAt (size_t nIndex, size_t count=1)
	Removes count items starting at position nIndex from the array.
void	Shrink ()
	Releases the extra memory allocated by the array.
void	Sort (bool reverseOrder=false)
	Sorts the array in alphabetical order or in reverse alphabetical order if reverseOrder is true.
void	Sort (CompareFunction compareFunction)
	Sorts the array using the specified compareFunction for item comparison.
bool	operator!= (const wxArrayString &array) const
	Compares 2 arrays respecting the case.
wxArrayString &	operator= (const wxArrayString &)
	Assignment operator.
bool	operator== (const wxArrayString &array) const
	Compares 2 arrays respecting the case.
wxString &	operator[] (size_t nIndex) const
	Return the array element at position nIndex.
	wxArrayString (size_t sz, const char **arr)
	Constructor from a C string array.
	wxArrayString (size_t sz, const wchar_t **arr)
	Constructor from a C string array.
wxString &	Item (size_t nIndex)
	Return the array element at position nIndex.
const wxString &	Item (size_t nIndex) const
	Return the array element at position nIndex.
wxString &	Last ()
	Returns the last element of the array.
const wxString &	Last () const
	Returns the last element of the array.

Member Typedef Documentation

typedef int(* wxArrayString::CompareFunction)(const wxString &first, const wxString &second)

The function type used with wxArrayString::Sort().

This function uses the same conventions as the standard qsort() comparison function, that is it should return a negative value if the first argument is less than the second one, a positive value if the first argument is greater than the second one and 0 if the arguments are equal.

Since

3.1.0

Constructor & Destructor Documentation

wxArrayString::wxArrayString

(

)

Default constructor.

wxArrayString::wxArrayString

(

const wxArrayString &

array

)

Copy constructor.

wxArrayString::wxArrayString	(	size_t	sz,
		const char **	arr
	)

Constructor from a C string array.

Pass a size sz and an array arr.

wxArrayString::wxArrayString	(	size_t	sz,
		const wchar_t **	arr
	)

Constructor from a C string array.

Pass a size sz and an array arr.

wxArrayString::wxArrayString	(	size_t	sz,
		const wxString *	arr
	)

Constructor from a wxString array.

Pass a size sz and array arr.

wxArrayString::~wxArrayString

(

)

Destructor frees memory occupied by the array strings.

For performance reasons it is not virtual, so this class should not be derived from.

Member Function Documentation

size_t wxArrayString::Add	(	const wxString &	str,
		size_t	copies = 1
	)

Appends the given number of copies of the new item str to the array and returns the index of the first new item in the array.

See Also

Insert()

void wxArrayString::Alloc

(

size_t

nCount

)

Preallocates enough memory to store nCount items.

This function may be used to improve array class performance before adding a known number of items consecutively.

void wxArrayString::Clear

(

)

Clears the array contents and frees memory.

See Also

Empty()

void wxArrayString::Empty

(

)

Empties the array: after a call to this function GetCount() will return 0.

However, this function does not free the memory used by the array and so should be used when the array is going to be reused for storing other strings. Otherwise, you should use Clear() to empty the array and free memory.

size_t wxArrayString::GetCount

(

)

const

Returns the number of items in the array.

int wxArrayString::Index	(	const wxString &	sz,
		bool	bCase = true,
		bool	bFromEnd = false
	)		const

Search the element in the array, starting from the beginning if bFromEnd is false or from end otherwise.

If bCase, comparison is case sensitive (default), otherwise the case is ignored.

This function uses linear search for wxArrayString. Returns index of the first item matched or wxNOT_FOUND if there is no match.

void wxArrayString::Insert	(	wxString	lItem,
		size_t	nIndex,
		size_t	copies = 1
	)

Insert the given number of copies of the new element in the array before the position nIndex.

Thus, for example, to insert the string in the beginning of the array you would write:

Insert("foo", 0);

If nIndex is equal to GetCount() this function behaves as Add().

bool wxArrayString::IsEmpty

(

)

const

Returns true if the array is empty, false otherwise.

This function returns the same result as GetCount() == 0 but is probably easier to read.

wxString& wxArrayString::Item

(

size_t

nIndex

)

Return the array element at position nIndex.

An assert failure will result from an attempt to access an element beyond the end of array in debug mode, but no check is done in release mode.

See Also

operator[] for the operator version.

const wxString& wxArrayString::Item

(

size_t

nIndex

)

const

Return the array element at position nIndex.

An assert failure will result from an attempt to access an element beyond the end of array in debug mode, but no check is done in release mode.

See Also

operator[] for the operator version.

wxString& wxArrayString::Last

(

)

Returns the last element of the array.

Attempt to access the last element of an empty array will result in assert failure in debug build, however no checks are done in release mode.

const wxString& wxArrayString::Last

(

)

const

Returns the last element of the array.

Attempt to access the last element of an empty array will result in assert failure in debug build, however no checks are done in release mode.

bool wxArrayString::operator!=

(

const wxArrayString &

array

)

const

Compares 2 arrays respecting the case.

Returns true if the arrays have different number of elements or if the elements don't match pairwise.

wxArrayString& wxArrayString::operator=

(

const wxArrayString &

)

Assignment operator.

bool wxArrayString::operator==

(

const wxArrayString &

array

)

const

Compares 2 arrays respecting the case.

Returns true only if the arrays have the same number of elements and the same strings in the same order.

wxString& wxArrayString::operator[]

(

size_t

nIndex

)

const

Return the array element at position nIndex.

An assert failure will result from an attempt to access an element beyond the end of array in debug mode, but no check is done in release mode.

This is the operator version of the Item() method.

void wxArrayString::Remove

(

const wxString &

sz

)

Removes the first item matching this value.

An assert failure is provoked by an attempt to remove an element which does not exist in debug build.

See Also

Index()

void wxArrayString::RemoveAt	(	size_t	nIndex,
		size_t	count = 1
	)

Removes count items starting at position nIndex from the array.

void wxArrayString::Shrink

(

)

Releases the extra memory allocated by the array.

This function is useful to minimize the array memory consumption.

See Also

Alloc()

void wxArrayString::Sort

(

bool

reverseOrder = false

)

Sorts the array in alphabetical order or in reverse alphabetical order if reverseOrder is true.

The sort is case-sensitive.

void wxArrayString::Sort

(

CompareFunction

compareFunction

)

Sorts the array using the specified compareFunction for item comparison.

CompareFunction is defined as a function taking two const wxString& parameters and returning an int value less than, equal to or greater than 0 if the first string is less than, equal to or greater than the second one.

Example: The following example sorts strings by their length.

static int CompareStringLen(const wxString& first, const wxString& second)
{
    return first.length() - second.length();
}

...

wxArrayString array;

array.Add("one");
array.Add("two");
array.Add("three");
array.Add("four");

array.Sort(CompareStringLen);