php函数集

统计数组元素个数

php$arr = array(      '1011,1003,1008,1001,1000,1004,1012',      '1009',      '1011,1003,1111'    );$result = array();foreach ($arr as $str) {  $str_arr = explode(',', $str);  foreach ($str_arr as $v) {    // $result[$v] = isset($result[$v]) ? $result[$v] : 0;    // $result[$v] = $result[$v] + 1;    $result[$v] = isset($result[$v]) ? $result[$v]+1 : 1;  }}

print_r($result);
//Array
(
[1011] => 2
[1003] => 2
[1008] => 1
[1001] => 1
[1000] => 1
[1004] => 1
[1012] => 1
[1009] => 1
[1111] => 1
)
2. 循环删除目录

phpfunction cleanup_directory($dir) {  foreach (new DirectoryIterator($dir) as $file) {    if ($file->isDir()) {      if (! $file->isDot()) {        cleanup_directory($file->getPathname());      }    } else {       unlink($file->getPathname());    }  }   rmdir($dir);}

3.无限极分类生成树

php<br />function generateTree($items){    $tree = array();    foreach($items as $item){        if(isset($items[$item['pid']])){            $items[$item['pid']]['son'][] = &$items[$item['id']];        }else{            $tree[] = &$items[$item['id']];        }    }    return $tree;}function generateTree2($items){    foreach($items as $item)        $items[$item['pid']]['son'][$item['id']] = &$items[$item['id']];    return isset($items[0]['son']) ? $items[0]['son'] : array();}$items = array(    1 => array('id' => 1, 'pid' => 0, 'name' => '安徽省'),    2 => array('id' => 2, 'pid' => 0, 'name' => '浙江省'),    3 => array('id' => 3, 'pid' => 1, 'name' => '合肥市'),    4 => array('id' => 4, 'pid' => 3, 'name' => '长丰县'),    5 => array('id' => 5, 'pid' => 1, 'name' => '安庆市'),);print_r(generateTree($items));/** * 如何取数据格式化的树形数据 */$tree = generateTree($items);function getTreeData($tree){    foreach($tree as $t){        echo $t['name'].'<br>';        if(isset($t['son'])){            getTreeData($t['son']);        }    }}

4.数组排序 a - b 是数字数组写法 遇到字符串的时候就要

phpvar test = ['ab', 'ac', 'bd', 'bc'];test.sort(function(a, b) {    if(a < b) {        return -1;    }    if(a > b) {        return 1;    }    return 0;});

array_reduce

php$raw = [1,2,3,4,5,];// array_reduce 的第三个参数是 $result 的初始值array_reduce($raw, function($result, $value) {    $result[$value] = $value;    return $result;}, []);// [1 => 1, 2 => 2, ... 5 => 5]

6.array_map 闭包中只接受一个或者多个参数，闭包的参数数量和 array_map 本身的参数数量必须一致

php$input = ['key' => 'value'];array_map(function($key, $value) {    echo $key . $value;}, array_keys($input), $input)// 'keyvalue'

7.繁殖兔子

php$month = 12;   $fab = array();   $fab[0] = 1;   $fab[1] = 1;     for ($i = 2; $i < $month; $i++)     {         $fab[$i] = $fab[$i - 1] + $fab[$i - 2];     }     for ($i = 0; $i < $month; $i++)     {         echo sprintf("第{%d}个月兔子为：{%d}",$i, $fab[$i])."<br/>";     }

8 .datetime

phpfunction getCurMonthFirstDay($date){    return date('Y-m-01', strtotime($date));} getCurMonthLastDay('2015-07-23')function getCurMonthLastDay($date){    return date('Y-m-d', strtotime(date('Y-m-01', strtotime($date)) . ' +1 month -1 day'));}