C++ 맵 find()

1 개요

C++ 맵 find()

#include <iostream>
#include <map>
using namespace std;

int main() {
    map<string, int> m;
    m["a"] = 40;
    m["b"] = -74;
    
    cout << (m.find("a") != m.end()) << endl; // 1 (exists)
    cout << (m.find("x") != m.end()) << endl; // 0 (not exists)
}

#include <iostream>
#include <map>
using namespace std;

int main() {
    map<string, int> m = {{"apple",40},{"lemon",-74}};
    cout << m.find("apple")->second << endl; // 40
    cout << m.find("lemon")->second << endl; // -74
    cout << m.find("onion")->second << endl; // 1864668064 (not exists)
}

#include <iostream>
#include <map>
using namespace std;

int main() {
    map<string,int> m = {{"apple",40},{"lemon",-74}};
    map<string,int>::iterator it;
    it = m.find("apple");
    if(it == m.end()) {
        cout << "not found" << endl;
    } else {
        cout << it->second << endl; // 40
    }
    it = m.find("onion");
    if(it == m.end()) {
        cout << "not found" << endl; // not found
    } else {
        cout << it->second << endl;
    }
}

2 같이 보기

• C++ 맵
• C++ find()
• C++ 맵 키 있는지 확인

3 참고

• https://cplusplus.com/reference/map/map/find/