search
HomeBackend DevelopmentPHP TutorialHierarchical processing code for infinite hierarchical data in PHP array_PHP tutorial

Hierarchical processing code for infinite hierarchical data in PHP array_PHP tutorial

Jul 21, 2016 pm 03:13 PM
phpcodeGradinglistcreateparameterdeal withcopyHierarchydataarrayunlimitedfatherofnode

复制代码 代码如下:

/**
* Create a parent node tree array
* Parameters
* $ar array, data organized in adjacency list
* $id The subscript or associated key name as the primary key in the array
* $pid The subscript or associated key name as the parent key in the array
* Returns a multi-dimensional array
**/
function find_parent($ar, $id='id', $pid='pid') {
  foreach($ar as $v) $t[$v[$id]] = $v;
  foreach ($t as $k => $item){
    if( $item[$pid] ){
      if( ! isset($t[$item[$pid]]['parent'][$item[$pid]]) )
         $t[$item[$id]]['parent'][$item[$pid]] =& $t[$item[$pid]];
          $t[$k]['reference'] = true;
    }
  }
  return $t;
}
/**
* Create a tree array of child nodes
* Parameters
* $ar array, data organized in adjacency list
* $id The subscript or associated key name as the primary key in the array
* $pid The subscript or associated key name as the parent key in the array
* Returns a multi-dimensional array
**/
function find_child($ar, $id='id', $pid='pid') {
  foreach($ar as $v) $t[$v[$id]] = $v;
  foreach ($t as $k => $item){
    if( $item[$pid] ) {
      $t[$item[$pid]]['child'][$item[$id]] =& $t[$k];
      $t[$k]['reference'] = true;
    }
  }
  return $t;
}

示例:
复制代码 代码如下:

$data = array(
    array('ID'=>1, 'PARENT'=>0, 'NAME'=>'祖父'),
    array('ID'=>2, 'PARENT'=>1, 'NAME'=>'父亲'),
    array('ID'=>3, 'PARENT'=>1, 'NAME'=>'叔伯'),
    array('ID'=>4, 'PARENT'=>2, 'NAME'=>'自己'),
    array('ID'=>5, 'PARENT'=>4, 'NAME'=>'儿子')
);
$p = find_parent($data, 'ID', 'PARENT');
$c = find_child($data, 'ID', 'PARENT');

上面两种方法是将所有节点按id平摊到一个数组中,然后找到他们的 parent 或 children ,通过引用将 平摊的元素挂接到 parent 、children 下,
但被引用的元素依然存在于平摊的数组中,因此,在实际应用时,最好标记那些被引用的元素,以避免以他们为根开始遍历,导致重复。
复制代码 代码如下:

        foreach ($p as $key => $item) {
            if($item['reference']) continue;
            print_r($item);
        }
        foreach ($c as $key => $item) {
            if($item['reference']) continue;
            print_r($item);
        }

递归法,PHP 数组元素被删除后,数组游标会归零,因此在遍历过程中一些已经找到 “归宿” 的元素也不得不留在数组中,无法缩减后继元素的搜索范围:
复制代码 代码如下:

$mylist = array(array( 'parent_id'=>0,'id'=>1),
                    array( 'parent_id'=>0,'id'=>2),
                    array( 'parent_id'=>0,'id'=>3),   
                    array( 'parent_id'=>2,'id'=>4),
                    array( 'parent_id'=>2,'id'=>5),
                    array( 'parent_id'=>3,'id'=>6),
                    array( 'parent_id'=>3,'id'=>7),   
                    array( 'parent_id'=>4,'id'=>8),
                    array( 'parent_id'=>5,'id'=>9),
                    array( 'parent_id'=>5,'id'=>10)
                );

    function _findChildren($list, $p_id){    //数据层级化,
          $r = array();
          foreach($list as $id=>$item){
            if($item['parent_id'] == $p_id) {
                   $length = count($r);
                  $r[$length] = $item;
                  if($t = $this->_findChildren($list, $item['id']) ){
                      $r[$length]['children'] = $t;
                  }               
            }
          }
          return $r;
    } 

print_r(_findChildren($mylist, 0));

www.bkjia.comtruehttp://www.bkjia.com/PHPjc/326411.htmlTechArticle复制代码 代码如下: /** * 创建父节点树形数组 * 参数 * $ar 数组,邻接列表方式组织的数据 * $id 数组中作为主键的下标或关联键名 * $pid 数组...
Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Explain how load balancing affects session management and how to address it.Explain how load balancing affects session management and how to address it.Apr 29, 2025 am 12:42 AM

Load balancing affects session management, but can be resolved with session replication, session stickiness, and centralized session storage. 1. Session Replication Copy session data between servers. 2. Session stickiness directs user requests to the same server. 3. Centralized session storage uses independent servers such as Redis to store session data to ensure data sharing.

Explain the concept of session locking.Explain the concept of session locking.Apr 29, 2025 am 12:39 AM

Sessionlockingisatechniqueusedtoensureauser'ssessionremainsexclusivetooneuseratatime.Itiscrucialforpreventingdatacorruptionandsecuritybreachesinmulti-userapplications.Sessionlockingisimplementedusingserver-sidelockingmechanisms,suchasReentrantLockinJ

Are there any alternatives to PHP sessions?Are there any alternatives to PHP sessions?Apr 29, 2025 am 12:36 AM

Alternatives to PHP sessions include Cookies, Token-based Authentication, Database-based Sessions, and Redis/Memcached. 1.Cookies manage sessions by storing data on the client, which is simple but low in security. 2.Token-based Authentication uses tokens to verify users, which is highly secure but requires additional logic. 3.Database-basedSessions stores data in the database, which has good scalability but may affect performance. 4. Redis/Memcached uses distributed cache to improve performance and scalability, but requires additional matching

Define the term 'session hijacking' in the context of PHP.Define the term 'session hijacking' in the context of PHP.Apr 29, 2025 am 12:33 AM

Sessionhijacking refers to an attacker impersonating a user by obtaining the user's sessionID. Prevention methods include: 1) encrypting communication using HTTPS; 2) verifying the source of the sessionID; 3) using a secure sessionID generation algorithm; 4) regularly updating the sessionID.

What is the full form of PHP?What is the full form of PHP?Apr 28, 2025 pm 04:58 PM

The article discusses PHP, detailing its full form, main uses in web development, comparison with Python and Java, and its ease of learning for beginners.

How does PHP handle form data?How does PHP handle form data?Apr 28, 2025 pm 04:57 PM

PHP handles form data using $\_POST and $\_GET superglobals, with security ensured through validation, sanitization, and secure database interactions.

What is the difference between PHP and ASP.NET?What is the difference between PHP and ASP.NET?Apr 28, 2025 pm 04:56 PM

The article compares PHP and ASP.NET, focusing on their suitability for large-scale web applications, performance differences, and security features. Both are viable for large projects, but PHP is open-source and platform-independent, while ASP.NET,

Is PHP a case-sensitive language?Is PHP a case-sensitive language?Apr 28, 2025 pm 04:55 PM

PHP's case sensitivity varies: functions are insensitive, while variables and classes are sensitive. Best practices include consistent naming and using case-insensitive functions for comparisons.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

WebStorm Mac version

WebStorm Mac version

Useful JavaScript development tools

SAP NetWeaver Server Adapter for Eclipse

SAP NetWeaver Server Adapter for Eclipse

Integrate Eclipse with SAP NetWeaver application server.

Safe Exam Browser

Safe Exam Browser

Safe Exam Browser is a secure browser environment for taking online exams securely. This software turns any computer into a secure workstation. It controls access to any utility and prevents students from using unauthorized resources.

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),