How to sort an array in ascending order in php

3 ascending order methods: 1. Use the "sort(array, sorting mode)" statement to sort the array elements in ascending order; 2. Use the "asort(array, sorting mode)" statement to sort the array elements according to the key Sort the array elements in ascending order by value; 3. Use the "ksort(array, sort mode)" statement to sort the array elements in ascending order based on the key name.

The operating environment of this tutorial: Windows 7 system, PHP version 7.1, DELL G3 computer

There are three commonly used ascending array sorting functions in PHP :

• sort(): Sort the array elements in ascending order

• asort(): Sort the array in ascending order according to the key value of the associated array Arrange

• ksort(): Sort the array in ascending order according to the key name of the associated array

1. Use sort() Function

sort() function sorts the array elements in ascending order (from small to large, from low to high).

The sort() function has two parameters: $array (required) and $sortingtype (can be omitted).

Among them, the $sortingtype parameter is used to define the function sorting mode and specify how to compare the elements/items of the array. The default value is "SORT_REGULAR".

The $sortingtype parameter can be set to the following values:

• 0 = SORT_REGULAR: Compare array elements normally without changing their type (default value);

• 1 = SORT_NUMERIC: Treat array elements as numbers;

• ##2 = SORT_STRING: Treat array elements as strings;

• 3 = SORT_LOCALE_STRING: Compare array elements as strings based on the current locale (can be changed via setlocale()).

• 4 = SORT_NATURAL: Similar to natsort(), it sorts strings in "natural order" for each array element. It is new in PHP5.4.0.

• 5 = SORT_FLAG_CASE: Can be combined with SORT_STRING or SORT_NATURAL (OR bitwise operation), case-insensitive sorting string.

Example 1: Not setting the second parameter

<?php
header("Content-type:text/html;charset=utf-8");
$arr1=array(10, 23, 5, 12, 84, 16);
sort($arr1);
var_dump($arr1);

$arr2=array("香蕉","苹果","梨子","橙子","橘子","榴莲");
sort($arr2);
var_dump($arr2);
?>

Example 2: Setting the second parameter

<?php
header("Content-type:text/html;charset=utf-8");
$arr1 = array(10, 23, 5, 12, 84, 16);
sort($arr1,2);
var_dump($arr1);

$arr2= array("香蕉","苹果","梨子","橙子","橘子","榴莲");
sort($arr2,1);
var_dump($arr2);
?>

The sort() function will not maintain the index relationship, but will delete the original key name in the array and assign it a new numerical key name.

2. Use the asort() function

The asort() function will sort the associative array in ascending order based on the key values ​​and will not modify the key names in the original array. .

<?php
header("Content-type:text/html;charset=utf-8");
$age = array("张三"=>30,"李四"=>23,"王五"=>15,"李华"=>12,"娜娜"=>26,"小红"=>16);
asort($age);
var_dump($age);
?>

Output:

asort() function also has two parameters, the parameter values ​​are the same as the sort() function, you can refer to.

3. Use the ksort() function

The ksort() function will sort the associated array in ascending order according to the key name, and will not modify the original array. key name.

<?php
header("Content-type:text/html;charset=utf-8");
$arr= array("l"=>"lemon", "o"=>"orange", "b"=>"banana", "a"=>"apple");
ksort($arr);
var_dump($arr);
?>

ksort() function also has two parameters. The parameter values ​​are the same as the sort() function, you can refer to them.

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