CMapStringToOb::Lookup

Статья
10/16/2008

Returns a CObject pointer based on a CString value.

BOOL Lookup(
   LPCTSTR key,
   CObject*& rValue 
) const;

Параметры

key
Specifies the string key that identifies the element to be looked up.
rValue
Specifies the returned value from the looked-up element.

Возвращаемое значение

Nonzero if the element was found; otherwise 0.

Заметки

Lookup uses a hashing algorithm to quickly find the map element with a key that matches exactly (CString value).

The following table shows other member functions that are similar to CMapStringToOb::LookUp.

Class	Member Function
CMapPtrToPtr	BOOL Lookup( void* key, void& rValue ) const;*
CMapPtrToWord	BOOL Lookup( void* key, WORD& rValue ) const;
CMapStringToPtr	BOOL Lookup( LPCTSTR key, void& rValue ) const;*
CMapStringToString	BOOL Lookup( LPCTSTR key, CString& rValue ) const;
CMapWordToOb	BOOL Lookup( WORD key, CObject& rValue ) const;*
CMapWordToPtr	BOOL Lookup( WORD key, void& rValue ) const;*

Пример

See CObList::CObList for a listing of the CAge class used in all collection examples.

CMapStringToOb map;
CAge* pa;

map.SetAt(_T("Bart"), new CAge(13));
map.SetAt(_T("Lisa"), new CAge(11));
map.SetAt(_T("Homer"), new CAge(36));
map.SetAt(_T("Marge"), new CAge(35));
ASSERT(map.Lookup(_T("Lisa"), (CObject*&)pa)); // Is "Lisa" in the map?
ASSERT(*pa ==  CAge(11)); // Is she 11?