How to sort PHP array?
How to sort a PHP array?
In our daily PHP array development, sorting of arrays is indispensable in many projects. So there are several types of PHP arrays The sorting methods are: asort() function and ksort() function. Today I will introduce them to you one by one!
The first method: asort()
asort() function is to sort the array and maintain the index relationship
The syntax format is as follows:
bool sort ( array &$array [, int $sort_flags = SORT_REGULAR ] )
Sort type tag:
SORT_REGULAR - normal comparison unit (does not change type)
SORT_NUMERIC - Cells are compared as numbers
SORT_STRING - Cells are compared as strings
SORT_LOCALE_STRING - Based on the current locale Set to compare cells as strings, which can be changed with setlocale() .
SORT_NATURAL - Similar to natsort(), which sorts strings in "natural order" for each unit. New in PHP 5.4.0.
SORT_FLAG_CASE - Can be combined with SORT_STRING or SORT_NATURAL (OR bit operation), case-insensitive sorting strings.
Note: sort is mostly used to sort numerical index arrays. If an associative array is put into sort to sort, the keys of the array will be lost. In addition, UTF8 Chinese cannot be sorted.
The following is a small example of the sort function. The specific code is as follows:
<?php header("Content-Type:text/html; charset=utf-8"); $arr = ['g','h','d','a','z','F','b','c','e','A','f']; print_r($arr); sort($arr); // 从 A-Z, a-z, 数字从小到大 进行排序 print_r($arr); ?>
What happens if the value is a number and the sort function is used? Please look at the following code example:
<?php header("Content-Type:text/html; charset=utf-8"); $arr2 = [8,1,2,10,3,4,5]; print_r($arr2); sort($arr2); // 如果值是数子, 从小到大,进行排序 print_r($arr2); ?>
The output result is:
From the above example, we can see that if the value of the array is a number, use The sort() function will sort from smallest to largest!
The second method is to ascend the associative array: asort() and ksort()
asort() function sorts the array and maintains the index relationship.
Since associative arrays cannot be sorted using sort, what function should be used? We recommend using asort. The usage is the same as sort, but after sorting, the keys can still be retained.
The syntax format is as follows:
bool asort ( array &$array [, int $sort_flags = SORT_REGULAR ] )
The following is a small example of using the asort function. The code is as follows:
<?php header("Content-Type:text/html; charset=utf-8"); //$arr = array("one"=>"100","two"=>"300","400"=>"教程"); $arr['one'] = 100; $arr['two'] = 20; $arr['three'] = 3; asort($arr); // asort排序,键值会保留 print_r($arr); ?>
The output result is;
Note:
#Associative array is composed of keys and values, so what is asort? Sorted based on what?
We can prove that asort actually uses the values of the array to sort, then if we want to sort the keys, we can use ksort.The ksort() function sorts the array by key name.
The syntax format is as follows:bool ksort ( array &$array [, int $sort_flags = SORT_REGULAR ] )
<?php header("Content-Type:text/html; charset=utf-8"); //$arr = array("one"=>"100","two"=>"300","400"=>"教程"); $arr['one'] = 100; $arr['two'] = 20; $arr['three'] = 3; ksort($arr); //使用key值对数组进行排序 print_r($arr); ?>
PHP Array Reverse order》!
【Related tutorial recommendations】1. Relevant topic recommendations: "2. Related video course recommendations: 《Array sorting by value: sort() forward and rsort() reverse sorting functions》
《Array sorting by key name: ksort() ascending order and krsort() descending order function》
The above is the detailed content of How to sort PHP array?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

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

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics











PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.

PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
