C++声明一个Employee类，其中包括姓名、城市和邮编属性，以及change_name()和display()函数。display()函数显示姓名、城市和邮编属性，change_name()函数实现修改对象的姓名属性。声明包含2个元素的对象数组，每个元素都是Employee类型的对象。给对象赋值并输出。

以下是一个实现该功能的C++代码示例：

#include <iostream>
#include <string>

using namespace std;

class Employee {
public:
    string name;
    string city;
    int postal_code;

    void change_name(string new_name) {
        name = new_name;
    }

    void display() {
        cout << "Name: " << name << endl;
        cout << "City: " << city << endl;
        cout << "Postal Code: " << postal_code << endl;
    }
};

int main() {
    Employee employees[2];

    employees[0].name = "John";
    employees[0].city = "New York";
    employees[0].postal_code = 10001;

    employees[1].name = "Jane";
    employees[1].city = "Los Angeles";
    employees[1].postal_code = 90001;

    employees[0].display();
    cout << endl;
    employees[1].display();
    cout << endl;

    employees[0].change_name("Jack");

    employees[0].display();
    cout << endl;
    employees[1].display();
    cout << endl;

    return 0;
}

输出结果：

Name: John
City: New York
Postal Code: 10001

Name: Jane
City: Los Angeles
Postal Code: 90001

Name: Jack
City: New York
Postal Code: 10001

Name: Jane
City: Los Angeles
Postal Code: 90001