PHP获取以字母递增为键值的数组。

/**
 * 获取以字母递增为键值的数组
 * @param bool $capitalization
 * @param int $length
 * @return array
 */
function getCharList($capitalization = true, $length = 26) {
    $key = $capitalization ? 65/*大写字母*/ : 97/*小写字母*/;
    $list = array();
    for ($i = 1; $i <= $length; $i++) {
        $list[] = chr($key);
        $key++;
    }

    return $list;
}

示例：

echo '<pre>';print_r(getCharList(false));

打印结果如下：

Array
(
    [0] => a
    [1] => b
    [2] => c
    [3] => d
    [4] => e
    [5] => f
    [6] => g
    [7] => h
    [8] => i
    [9] => j
    [10] => k
    [11] => l
    [12] => m
    [13] => n
    [14] => o
    [15] => p
    [16] => q
    [17] => r
    [18] => s
    [19] => t
    [20] => u
    [21] => v
    [22] => w
    [23] => x
    [24] => y
    [25] => z
)