wxStringTokenizer helps you to break a string up into a number of tokens. It replaces the standard C function strtok() and also extends it in a number of ways.
To use this class, you should create a wxStringTokenizer object, give it the string to tokenize and also the delimiters which separate tokens in the string (by default, white space characters will be used).
Then GetNextToken may be called repeatedly until it HasMoreTokens returns false.
For example:
wxStringTokenizer tkz(wxT("first:second:third:fourth"), wxT(":"));
while ( tkz.HasMoreTokens() )
{
wxString token = tkz.GetNextToken();
// process token here
}
By default, wxStringTokenizer will behave in the same way as strtok() if
the delimiters string only contains white space characters but, unlike the
standard function, it will return empty tokens if this is not the case. This
is helpful for parsing strictly formatted data where the number of fields is
fixed but some of them may be empty (i.e. TAB or comma delimited text
files).The behaviour is governed by the last constructor/SetString parameter mode which may be one of the following:
| wxTOKEN_DEFAULT | Default behaviour (as described above): same as wxTOKEN_STRTOK if the delimiter string contains only whitespaces, same as wxTOKEN_RET_EMPTY otherwise |
| wxTOKEN_RET_EMPTY | In this mode, the empty tokens in the middle of the string will be returned, i.e. "a::b:" will be tokenized in three tokens 'a', '' and 'b'. Notice that all trailing delimiters are ignored in this mode, not just the last one, i.e. a string "a::b::" would still result in the same set of tokens. |
| wxTOKEN_RET_EMPTY_ALL | In this mode, empty trailing tokens (including the one after the last delimiter character) will be returned as well. The string "a::b:" will be tokenized in four tokens: the already mentioned ones and another empty one as the last one and a string "a::b::" will have five tokens. |
| wxTOKEN_RET_DELIMS | In this mode, the delimiter character after the end of the current token (there may be none if this is the last token) is returned appended to the token. Otherwise, it is the same mode as wxTOKEN_RET_EMPTY. Notice that there is no mode like this one but behaving like wxTOKEN_RET_EMPTY_ALL instead of wxTOKEN_RET_EMPTY, use wxTOKEN_RET_EMPTY_ALL and GetLastDelimiter() to emulate it. |
| wxTOKEN_STRTOK | In this mode the class behaves exactly like the standard strtok() function: the empty tokens are never returned. |
Derived from
See also
Include files
<wx/tokenzr.h>
Members
wxStringTokenizer::wxStringTokenizer
wxStringTokenizer::CountTokens
wxStringTokenizer::HasMoreTokens
wxStringTokenizer::GetLastDelimiter
wxStringTokenizer::GetNextToken
wxStringTokenizer::GetPosition
wxStringTokenizer::GetString
wxStringTokenizer::SetString
wxStringTokenizer()
Default constructor. You must call SetString before calling any other methods.
wxStringTokenizer(const wxString& str, const wxString& delims = " \t\r\n", wxStringTokenizerMode mode = wxTOKEN_DEFAULT)
Constructor. Pass the string to tokenize, a string containing delimiters and the mode specifying how the string should be tokenized.
int CountTokens() const
Returns the number of tokens remaining in the input string. The number of tokens returned by this function is decremented each time GetNextToken is called and when it reaches 0 HasMoreTokens returns false.
bool HasMoreTokens() const
Returns true if the tokenizer has further tokens, false if none are left.
wxChar GetLastDelimiter()
Returns the delimiter which ended scan for the last token returned by GetNextToken() or NUL if there had been no calls to this function yet or if it returned the trailing empty token in wxTOKEN_RET_EMPTY_ALL mode.
This function is new since wxWidgets version 2.7.0
wxString GetNextToken() const
Returns the next token or empty string if the end of string was reached.
size_t GetPosition() const
Returns the current position (i.e. one index after the last returned token or 0 if GetNextToken() has never been called) in the original string.
wxString GetString() const
Returns the part of the starting string without all token already extracted.
void SetString(const wxString& to_tokenize, const wxString& delims = " \t\r\n", wxStringTokenizerMode mode = wxTOKEN_DEFAULT)
Initializes the tokenizer.
Pass the string to tokenize, a string containing delimiters, and the mode specifying how the string should be tokenized.