Browse - Programming Tips - What happens when a key is missing from a std::map ?

Date: 2015apr24
Language: C++

Q.  What happens when a key is missing from a std::map<> ?

A.  It makes an empty entry then gives that to you.
If we have:


std::map<std::string, std::string> fruit; fruit["apple"] = "red"; fruit["bannana"] = "yellow";
Then we try to get:
std::string c = fruit["orange"];
String c will be "". Since its been added to the map. Note this as changed fruit.size() You can use fruit.find("orange") to see if a key is present.