+演算子のオーバーロード

#include < iostream >
using namespace std;

class coord {
    int x, y;
public:
    coord() { x=0; y=0; }
    coord(int i, int j){ x=i; y=j; }
    void get_xy(int &i, int &j){ i=x; j=y; }
    coord operator+(coord ob2);
    coord operator+(int i);
};

coord coord::operator+(coord ob2)
{
    coord temp;
    
    temp.x = x + ob2.x;
    temp.y = y + ob2.y;
    
    return temp;
}

coord coord::operator+(int i)
{
    coord temp;
    
    temp.x = x + i;
    temp.y = y + i;
    
    return temp;
}

int main()
{
    coord o1(10, 10), o2(5, 3), o3;
    int x, y;
    
    o3 = o1 + o2;
    o3.get_xy(x, y);
    cout << "(o1+o2) x: " << x << ", Y: " << y << "\n";
    
    o3 = o1 + 100;
    o3.get_xy(x, y);
    cout << "(o1+100) x: " << x << ", Y: " << y << "\n";
    
    return 0;
}

参照　swap

#include < iostream >
using namespace std;

void swapargs(int &x, int &y);

int main()
{
    int i, j;
    
    i = 10;
    j = 19;
    
    cout << "i: " << i << ", ";
    cout << "j: " << j << "\n";
    
    swapargs(i, j);
    
    cout << "after exchange: ";
    cout << "i: " << i << ", ";
    cout << "j: " << j << "\n";
    
    return 0;
}

void swapargs(int &x, int &y)
{
    int t;
    
    t = x;
    x = y;
    y = t;
}

整数の配列の割り当て

#include < iostream >
using namespace std;

int main()
{
    int *p;
    
    p = new int [5];
    
    if(!p) {
        cout << "memory set error\n";
        return 1;
    }
    
    int i;
    
    for(i=0; i<5; i++) p[i] = i;
    
    for(i=0; i<5; i++){
        cout << "integer type p[" << i << "]is: ";
        cout << p[i] << "\n";
    }
    
    delete [] p;
    
    return 0;
}

オブジェクトを動的に割り当て

#include 
using namespace std;

class samp {
    int i, j;
public:
    void set_ij(int a, int b){ i=a; j=b; }
    int get_product() { return i*j; }
};

int main()
{
    samp *p;
    
    p = new samp;
    if(!p){
        cout << "memory set error\n";
        return 1;
    }
    
    p->set_ij(4, 5);
    cout << "multiply is :" << p->get_product() << "\n";
    delete p;
    return 0;
}

newとdelete

#include < iostream >
using namespace std;

int main()
{
    int *p;
    
    p = new int;
    if(!p) {
        cout << "memory set error\n";
        return 1;
    }
    
    *p = 1000;
    cout << "p point integer is: " << *p << "\n";
    delete p;
    return 0;
}

thisポインタ

メンバ関数から同じクラスのほかのメンバを参照する際には、直接参照することができる。

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

class inventory {
    char item[20];
    double cost;
    int on_hand;
public:
    
    inventory(char *i, double c, int o)
    {
        strcpy(item, i);
        cost = c;
        on_hand = o;
    }
    void show();
};

void inventory::show()
{
    cout << item;
    cout << ": $" << cost;
    cout << " stock: " << on_hand << "\n";
}

int main()
{
    inventory ob("rench", 4.95, 4);
    ob.show();
    return 0;
}

コンストラクタに複数の引数

#include < iostream >
using namespace std;

class samp {
    int a, b;
public:
    samp(int n, int m){ a = n; b = m; }
    int get_a() { return a; }
    int get_b() { return b; }
};

int main()
{
    samp ob[4][2] = {
        samp(1, 2), samp(3, 4),
        samp(5, 6), samp(7, 8),
        samp(9, 10), samp(11, 12),
        samp(13, 14), samp(15, 16)
    };
    
    int i;
    
    for(i = 0; i<4; i++){
        cout << ob[i][0].get_a() << ' ';
        cout << ob[i][0].get_b() << "\n";
        cout << ob[i][1].get_a() << ' ';
        cout << ob[i][1].get_b() << "\n";
        
    }
    cout << "\n";
    return 0;
}

オブジェクトの多次元配列

#include < iostream >
using namespace std;

class samp {
    int a;
public:
    samp(int n){ a = n; }
    int get_a() { return a; }
};

int main()
{
    samp ob[4][2] = {
        1, 2,
        3, 4,
        5, 6,
        7, 8
    };
    int i;
    
    for (i=0; i<4; i++){
        cout << ob[i][0].get_a() << ' ';
        cout << ob[i][1].get_a() << "\n";
    }
    cout << "\n";
    
    return 0;
}