map::operator(STL/CLR)
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The latest version of this topic can be found at map::operator(STL/CLR).
Maps a key to its associated mapped value.
Syntax
mapped_type operator[](key_type key);
Parameters
key
Key value to search for.
Remarks
The member functions endeavors to find an element with equivalent ordering to key. If it finds one, it returns the associated mapped value; otherwise, it inserts value_type(``key``, mapped_type()) and returns the associated (default) mapped value. You use it to look up a mapped value given its associated key, or to ensure that an entry exists for the key if none is found.
Example
// cliext_map_operator_sub.cpp
// compile with: /clr
#include <cliext/map>
typedef cliext::map<wchar_t, int> Mymap;
int main()
{
Mymap c1;
c1.insert(Mymap::make_value(L'a', 1));
c1.insert(Mymap::make_value(L'b', 2));
c1.insert(Mymap::make_value(L'c', 3));
// display contents " [a 1] [b 2] [c 3]"
for each (Mymap::value_type elem in c1)
System::Console::Write(" [{0} {1}]", elem->first, elem->second);
System::Console::WriteLine();
System::Console::WriteLine("c1[{0}] = {1}",
L'A', c1[L'A']);
System::Console::WriteLine("c1[{0}] = {1}",
L'b', c1[L'b']);
// redisplay altered contents
for each (Mymap::value_type elem in c1)
System::Console::Write(" [{0} {1}]", elem->first, elem->second);
System::Console::WriteLine();
// alter mapped values and redisplay
c1[L'A'] = 10;
c1[L'c'] = 13;
for each (Mymap::value_type elem in c1)
System::Console::Write(" [{0} {1}]", elem->first, elem->second);
System::Console::WriteLine();
return (0);
}
[a 1] [b 2] [c 3]
c1[A] = 0
c1[b] = 2
[A 0] [a 1] [b 2] [c 3]
[A 10] [a 1] [b 2] [c 13]
Requirements
Header: <cliext/map>
Namespace: cliext