16个常见的php基本函数

本文给大家汇总了16个常见的php基本函数，涵盖的面很广，这里推荐给大家，希望对大家学习php能够有所帮助。

1.统计数组元素个数

$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

function 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

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 $t[&#39;name&#39;].&#39;<br>&#39;;
    if(isset($t[&#39;son&#39;])){
      getTreeData($t[&#39;son&#39;]);
    }
  }
}

4.数组排序 a - b 是数字数组写法 遇到字符串的时候就要

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

5.array_reduce

$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

$input = ['key' => 'value'];
array_map(function($key, $value) {
  echo $key . $value;
}, array_keys($input), $input)
// 'keyvalue'
$double = function($item) {
 return 2 * $item;
}
$result = array_map($double, [1,2,3]);
// 2 4 6

7.繁殖兔子

$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

function 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'));
}

9.加密解密

function encrypt($data, $key)
{
  $key  =  md5($key);
  $x   =  0;
  $len  =  strlen($data);
  $l   =  strlen($key);
  $char  =  '';
  for ($i = 0; $i < $len; $i++)
  {
    if ($x == $l)
    {
      $x = 0;
    }
    $char .= $key{$x};
    $x++;
  }
  $str  =  &#39;&#39;;
  for ($i = 0; $i < $len; $i++)
  {
    $str .= chr(ord($data{$i}) + (ord($char{$i})) % 256);
  }
  return base64_encode($str);
}
function decrypt($data, $key)
{
  $key = md5($key);
  $x = 0;
  $data = base64_decode($data);
  $len = strlen($data);
  $l = strlen($key);
  $char = &#39;&#39;;
  for ($i = 0; $i < $len; $i++)
  {
    if ($x == $l)
    {
      $x = 0;
    }
    $char .= substr($key, $x, 1);
    $x++;
  }
  $str = &#39;&#39;;
  for ($i = 0; $i < $len; $i++)
  {
    if (ord(substr($data, $i, 1)) < ord(substr($char, $i, 1)))
    {
      $str .= chr((ord(substr($data, $i, 1)) + 256) - ord(substr($char, $i, 1)));
    }
    else
    {
      $str .= chr(ord(substr($data, $i, 1)) - ord(substr($char, $i, 1)));
    }
  }
  return $str;
}

10 . 多维数组降级

function array_flatten($arr) {
  $result = [];
  array_walk_recursive($arr, function($value) use (&$result) {
    $result[] = $value;
  });
  return $result;
}
print_r(array_flatten([1,[2,3],[4,5]]));// [1,[2,3],[4,5]] => [1,2,3,4,5]
// var new_array = old_array.concat(value1[, value2[, ...[, valueN]]])
var test = [1,2,3,[4,5,6],[7,8]];
[].concat.apply([], test); // [1,2,3,4,5,6,7,8] 对于 test 数组中的每一个 value， 将它 concat 到空数组 [] 中去，而因为 concat 是 Array 的 prototype，所以我们用一个空 array 作载体
var test1 = [1,2,[3,[4,[5]]]];
function flatten(arr) {
  return arr.reduce(function(pre, cur) {
    if(Array.isArray(cur)) {
      return flatten(pre.concat(cur));
    }
    return pre.concat(cur);
  }, []);
}
// [1,2,3,4,5]
json_encode中文
function json_encode_wrapper ($result)
{
  if(defined('JSON_UNESCAPED_UNICODE')){
    return json_encode($result,JSON_UNESCAPED_UNICODE|JSON_NUMERIC_CHECK);
  }else {
    return preg_replace(
      array("#\\\u([0-9a-f][0-9a-f][0-9a-f][0-9a-f])#ie", "/\"(\d+)\"/",),
      array("iconv('UCS-2', 'UTF-8', pack('H4', '\\1'))", "\\1"),
      json_encode($result)
    );
  }
}

12.二维数组去重

$arr = array(
  array('id'=>'2','title'=>'...','ding'=>'1','jing'=>'1','time'=>'...','url'=>'...','dj'=>'...'),
  array('id'=>'2','title'=>'...','ding'=>'1','jing'=>'1','time'=>'...','url'=>'...','dj'=>'...')
);
function about_unique($arr=array()){ 
  /*将该种二维数组看成一维数组，则   该一维数组的value值有相同的则干掉只留一个，并将该一维   数组用重排后的索引数组返回，而返回的一维数组中的每个元素都是   原始key值形成的关联数组  */  
$keys =array();
  $temp = array();
  foreach($arr[0] as $k=>$arrays) {
  /*数组记录下关联数组的key值*/   
  $keys[] = $k;
  }
  //return $keys;  /*降维*/  
foreach($arr as $k=>$v) {
  $v = join(",",$v); //降维   
  $temp[] = $v;
  }
  $temp = array_unique($temp); //去掉重复的内容  
foreach ($temp as $k => $v){
  /*再将拆开的数组按索引数组重新组装*/   
  $temp[$k] = explode(",",$v); 
  } 
  //return $temp;  /*再将拆开的数组按关联数组key值重新组装*/  
foreach($temp as $k=>$v) {
  foreach($v as $kkk=>$ck) {
   $data[$k][$keys[$kkk]] = $temp[$k][$kkk];
  }
  }
  return $data;
 }

13.格式化字节大小

/**
* 格式化字节大小
* @param number $size   字节数
* @param string $delimiter 数字和单位分隔符
* @return string      格式化后的带单位的大小
* @author 
*/
function format_bytes($size, $delimiter = '') {
 $units = array('B', 'KB', 'MB', 'GB', 'TB', 'PB');
 for ($i = 0; $size >= 1024 && $i < 6; $i++) $size /= 1024;
 return round($size, 2) . $delimiter . $units[$i];
}

14.3分钟前

/**
* 将指定时间戳转换为截止当前的xx时间前的格式 例如 return '3分钟前''
* @param string|int $timestamp unix时间戳
* @return string
*/
function time_ago($timestamp) {
  $etime = time() - $timestamp;
  if ($etime < 1) return &#39;刚刚&#39;;   
  $interval = array (     
   12 * 30 * 24 * 60 * 60 => &#39;年前 (&#39;.date(&#39;Y-m-d&#39;, $timestamp).&#39;)&#39;,
   30 * 24 * 60 * 60    => &#39;个月前 (&#39;.date(&#39;m-d&#39;, $timestamp).&#39;)&#39;,
   7 * 24 * 60 * 60    => &#39;周前 (&#39;.date(&#39;m-d&#39;, $timestamp).&#39;)&#39;,
   24 * 60 * 60      => &#39;天前&#39;,
   60 * 60         => &#39;小时前&#39;,
   60           => &#39;分钟前&#39;,
   1            => &#39;秒前&#39;
  );
  foreach ($interval as $secs => $str) {
    $d = $etime / $secs;
    if ($d >= 1) {
      $r = round($d);
      return $r . $str;
    }
  };
}

15.身份证号

/**
* 判断参数字符串是否为天朝身份证号
* @param $id 需要被判断的字符串或数字
* @return mixed false 或 array[有内容的array boolean为真]
*/
function is_citizen_id($id) {
  //长度效验 18位身份证中的X为大写
  $id = strtoupper($id);
  if(!(preg_match('/^\d{17}(\d|X)$/',$id) || preg_match('/^\d{15}$/',$id))) {
   return false;
  }
  //15位老号码转换为18位 并转换成字符串
  $Wi     = array(7, 9, 10, 5, 8, 4, 2, 1, 6, 3, 7, 9, 10, 5, 8, 4, 2, 1); 
  $Ai     = array('1', '0', 'X', '9', '8', '7', '6', '5', '4', '3', '2'); 
  $cardNoSum  = 0;
  if(strlen($id)==16) {
    $id    = substr(0, 6).'19'.substr(6, 9); 
    for($i = 0; $i < 17; $i++) {
     $cardNoSum += substr($id,$i,1) * $Wi[$i];
    } 
    $seq    = $cardNoSum % 11; 
    $id    = $id.$Ai[$seq];
  }
  //效验18位身份证最后一位字符的合法性
  $cardNoSum  = 0;
  $id17    = substr($id,0,17);
  $lastString = substr($id,17,1);
  for($i = 0; $i < 17; $i++) {
    $cardNoSum += substr($id,$i,1) * $Wi[$i];
  } 
  $seq     = $cardNoSum % 11;
  $realString = $Ai[$seq];
  if($lastString!=$realString) {return false;}
  //地域效验
  $oCity    = array(11=>"北京",12=>"天津",13=>"河北",14=>"山西",15=>"内蒙古",21=>"辽宁",22=>"吉林",23=>"黑龙江",31=>"上海",32=>"江苏",33=>"浙江",34=>"安徽",35=>"福建",36=>"江西",37=>"山东",41=>"河南",42=>"湖北",43=>"湖南",44=>"广东",45=>"广西",46=>"海南",50=>"重庆",51=>"四川",52=>"贵州",53=>"云南",54=>"西藏",61=>"陕西",62=>"甘肃",63=>"青海",64=>"宁夏",65=>"新疆",71=>"台湾",81=>"香港",82=>"澳门",91=>"国外");
  $City    = substr($id, 0, 2);
  $BirthYear  = substr($id, 6, 4);
  $BirthMonth = substr($id, 10, 2);
  $BirthDay  = substr($id, 12, 2);
  $Sex     = substr($id, 16,1) % 2 ;//男1 女0
  //$Sexcn    = $Sex?&#39;男&#39;:&#39;女&#39;;
  //地域验证
  if(is_null($oCity[$City])) {return false;}
  //出生日期效验
  if($BirthYear>2078 || $BirthYear<1900) {return false;}
  $RealDate  = strtotime($BirthYear.&#39;-&#39;.$BirthMonth.&#39;-&#39;.$BirthDay);
  if(date(&#39;Y&#39;,$RealDate)!=$BirthYear || date(&#39;m&#39;,$RealDate)!=$BirthMonth || date(&#39;d&#39;,$RealDate)!=$BirthDay) {
    return false;
  }
  return array(&#39;id&#39;=>$id,&#39;location&#39;=>$oCity[$City],&#39;Y&#39;=>$BirthYear,&#39;m&#39;=>$BirthMonth,&#39;d&#39;=>$BirthDay,&#39;sex&#39;=>$Sex);
}

16.获取二维数组中某个key的集合

$user = array( 0 => array( 'id' => 1, 'name' => '张三', 'email' => 'zhangsan@sina.com', ), 1 => array( 'id' => 2, 'name' => '李四', 'email' => 'lisi@163.com', ), 2 => array( 'id' => 5, 'name' => '王五', 'email' => '10000@qq.com', ), ...... );
$ids = array(); $ids = array_map('array_shift', $user);
$ids = array_column($user, 'id');//php5.5
$names = array(); $names = array_reduce($user, create_function('$v,$w', '$v[$w["id"]]=$w["name"];return $v;'));

总结：以上就是本篇文的全部内容，希望能对大家的学习有所帮助。

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