std::map::find
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| iterator find( const Key& key ); |
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| const_iterator find( const Key& key ) const; |
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Recherche un élément avec la clé
key. Original:
Finds an element with key
key. The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
Sommaire |
[modifier] Paramètres
| key | - | la valeur de clé de l'élément à rechercher
Original: key value of the element to search for The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. |
[modifier] Retourne la valeur
Itérateur pour un élément de
key clé. Si aucun élément correspondant n'est trouvé, past-the-end (voir end()) itérateur est renvoyé .Original:
Iterator to an element with key
key. If no such element is found, past-the-end (see end()) iterator is returned.The text has been machine-translated via Google Translate.
You can help to correct and verify the translation. Click here for instructions.
You can help to correct and verify the translation. Click here for instructions.
[modifier] Complexité
Logarithmic in the size of the container.
[modifier] Voir aussi
| retourne le nombre d'éléments correspondant à la clé spécifiée Original: returns the number of elements matching specific key The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction membre publique) | |
| rendements varient d'éléments correspondant à une clé spécifique Original: returns range of elements matching a specific key The text has been machine-translated via Google Translate. You can help to correct and verify the translation. Click here for instructions. (fonction membre publique) | |
[modifier] Exemple
Demonstrates the risk of accessing non-existing elements via operator [].
#include <string> #include <iostream> #include <map> int main() { typedef std::map<std::string,int> mapT; mapT my_map; my_map["first"]= 11; my_map["second"]= 23; mapT::iterator it= my_map.find("first"); if( it != my_map.end() ) std::cout << "A: " << it->second << "\n"; it= my_map.find("third"); if( it != my_map.end() ) std::cout << "B: " << it->second << "\n"; // Accessing a non-existing element creates it if( my_map["third"] == 42 ) std::cout << "Oha!\n"; it= my_map.find("third"); if( it != my_map.end() ) std::cout << "C: " << it->second << "\n"; return 0; }
Résultat :
A: 11 C: 0
