C++数组初始化方法详解

有时在程序中设置变量值比输入变量值更合适。但是，为数组的各个元素编写单独的赋值语句可能意味着大量的输入，对于大型数组而言尤其如此。

例如，来看一个程序：

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

int main()
{
    const int NUM_MONTHS = 12;
    int days[NUM_MONTHS];
    days[0] = 31; // January
    days[1] = 28; // February
    days[2] = 31; // March
    days[3] = 30; // April
    days[4] = 31; // May
    days[5] = 30; // June
    days[6] = 31; // July
    days[7] = 31; // August
    days[8] = 30; // September
    days[9] = 31; // October
    days[10] = 30; // November
    days[11] = 31; // December
    for (int month = 0; month < NUM_MONTHS; month++)
    {
        cout << "Month "<< setw (2) << (month+1) << " has ";
        cout << days[month] << " days.\n";
    }
    return 0;
}

程序输出结果：

Month 1 has 31 days.
Month 2 has 28 days.
Month 3 has 31 days.
Month 4 has 30 days.
Month 5 has 31 days.
Month 6 has 30 days.
Month 7 has 31 days.
Month 8 has 31 days.
Month 9 has 30 days.
Month 10 has 31 days.
Month 11 has 30 days.
Month 12 has 31 days.

幸运的是，还有一个选择，C++ 允许在定义数组时初始化数组。通过使用初始化列表，可以在创建数组时轻松初始化数组的所有元素。以下语句定义 days 数组，并使用之前程序中赋值语句集所建立的相同值对其进行初始化：

int days [NUM_MONTHS] = {31，28，31，30，31，30，31，31，30，31，30, 31};

这些值按照它们出现在列表中的顺序存储在数组元素中（第一个值 31 存储在 days[0] 中，第二个值 28 存储在 days [1] 中，等等）。图 1 显示了初始化后数组的内容。