Looks up the value mapped to a given key.
BOOL Lookup(
ARG_KEY key,
VALUE& rValue
) const;
Parameters
ARG_KEY
Template parameter specifying the type of the key value.key
Specifies the key that identifies the element to be looked up.VALUE
Specifies the type of the value to be looked up.rValue
Receives the looked-up value.
Return Value
Nonzero if the element was found; otherwise 0.
Remarks
Lookup uses a hashing algorithm to quickly find the map element with a key that exactly matches the given key.
Example
CMap<int,int,CPoint,CPoint> myMap;
myMap.InitHashTable(257);
// Add 200 elements to the map.
for (int i = 0; i < 200; i++)
myMap[i] = CPoint(i, i);
// Remove the elements with even key values.
CPoint pt;
for (int i = 0; myMap.Lookup(i, pt); i += 2)
{
myMap.RemoveKey(i);
}
ASSERT(myMap.GetSize() == 100);
TRACE(_T("myMap with %d elements:\n"), myMap.GetCount());
POSITION pos = myMap.GetStartPosition();
int iKey;
CPoint ptVal;
while (pos != NULL)
{
myMap.GetNextAssoc(pos, iKey, ptVal);
TRACE(_T("\t[%d] = (%d,%d)\n"), iKey, ptVal.x, ptVal.y);
}
Requirements
Header: afxtempl.h