[C++] 문법

기본 문법

#include <iostream>

using namespace std;

int main() {
    int a;
    int b;

    cin >> a >> b;
    cout << a << " + " << b << " = " << a + b << endl;

    return 0;
}

문자열

#include <iostream>

using namespace std;

int main() {
    string name;

    cin >> name;
    cout << name << endl;

    return 0;
}

foreach

#include <iostream>

using namespace std;

int main() {
    int arr[] = { 1, 2, 3, 4, 5 };

    for (int n : arr) {
        cout << n << endl;
    }

    return 0;
}

reference variable

#include <iostream>

using namespace std;

int main() {
    int a = 5;
    int &p = a;

    p = 10;

    cout << a << endl;
    cout << p << endl;

    return 0;
}

매개변수 초기화

#include <iostream>

using namespace std;

int sum(int a, int b = 1) {
    return a + b;
}

int main() {
    int number1 = sum(1, 5);
    int number2 = sum(1);

    cout << number1 << endl;
    cout << number2 << endl;

    return 0;
}

namespace

#include <iostream>

using namespace std;

int n;
void set() {
    n = 10;
}

namespace space1 {
    int n;
    void set() {
        n = 20;
    }
}

namespace space2 {
    int n;
    void set() {
        n = 30;
    }
}

int main() {
    ::set();
    space1::set();
    space2::set();

    cout << ::n << endl;
    cout << space1::n << endl;
    cout << space2::n << endl;

    return 0;
}