1. 0 ～ 9 の 10 個の数字を使用して 2 番目のディレクトリを作成します。各ディレクトリ名は 00/79 などの 2 桁で、すべてのディレクトリを出力します。

<?php$tmp = range(0,99);$res = array();foreach($tmp as $val){	if($val < 10){		array_push($res,'0'.$val);	}else{		array_push($res,$val);	}}print_r($res);?>#结果：Array ( [0] => 00 [1] => 01 [2] => 02 [3] => 03 [4] => 04 [5] => 05 [6] => 06 [7] => 07 [8] => 08 [9] => 09 [10] => 10 [11] => 11 [12] => 12 [13] => 13 [14] => 14 [15] => 15 [16] => 16 [17] => 17 [18] => 18 [19] => 19 [20] => 20 [21] => 21 [22] => 22 [23] => 23 [24] => 24 [25] => 25 [26] => 26 [27] => 27 [28] => 28 [29] => 29 [30] => 30 [31] => 31 [32] => 32 [33] => 33 [34] => 34 [35] => 35 [36] => 36 [37] => 37 [38] => 38 [39] => 39 [40] => 40 [41] => 41 [42] => 42 [43] => 43 [44] => 44 [45] => 45 [46] => 46 [47] => 47 [48] => 48 [49] => 49 [50] => 50 [51] => 51 [52] => 52 [53] => 53 [54] => 54 [55] => 55 [56] => 56 [57] => 57 [58] => 58 [59] => 59 [60] => 60 [61] => 61 [62] => 62 [63] => 63 [64] => 64 [65] => 65 [66] => 66 [67] => 67 [68] => 68 [69] => 69 [70] => 70 [71] => 71 [72] => 72 [73] => 73 [74] => 74 [75] => 75 [76] => 76 [77] => 77 [78] => 78 [79] => 79 [80] => 80 [81] => 81 [82] => 82 [83] => 83 [84] => 84 [85] => 85 [86] => 86 [87] => 87 [88] => 88 [89] => 89 [90] => 90 [91] => 91 [92] => 92 [93] => 93 [94] => 94 [95] => 95 [96] => 96 [97] => 97 [98] => 98 [99] => 99 ) 

// 递归目录名，理论上支持无限级目录，max是数字最大值function loopNames($level, $max){    static $data;    static $name;    for($i = 0; $i <= $max; $i++)    {        if ($level > 0)        {            $name[$level] = sprintf("%02d", $i);            loopNames($level - 1, $max);        }        else        {            $data[] = implode('/', $name);            break;        }    }    return $data;}set_time_limit(0);$t1 = microtime(true);$names = loopNames(2, 99);echo microtime(true) - $t1;print_r($names);// 输出结果10000条/*4.5159900188446Array(    [0] => 00/00    [1] => 00/01    [2] => 00/02    [3] => 00/03    [4] => 00/04    [5] => 00/05    [6] => 00/06    [7] => 00/07    [8] => 00/08    [9] => 00/09    [10] => 00/10    [11] => 00/11    [12] => 00/12    [13] => 00/13    [14] => 00/14    [15] => 00/15    [16] => 00/16    [17] => 00/17    [18] => 00/18    [19] => 00/19...*/