PHP数组排序函数合集 以及它们之间的联系分析
author:一佰互联 2019-04-29 click:171
下边提到的几个数组函数的排序有一些共性:
1 数组被作为排序函数的参数,排序以后,数组本身就发生了改变,函数的返回值为bool类型。
2 函数名中出现单a表示association,含义为,在按值排序的过程中,保持key=>value的对应关系不变
3 函数名中出现单k表示key,含义为,在按值排序的过程中按照数组key而不是数组的值排序
4 函数名中出现单r的表示reverse,含义为,按照跟不加r的相反的顺序排列
5 函数名中出现单u的表示user-defined,含义为,使用用户自定义函数排序,如果函数的逻辑是参数1<参数2返回负数,则按照升序排列(p1小2返负升)。
--------------------sort函数升序排序--------------------------------
复制代码 代码如下:
bool sort ( array &$array [, int $sort_flags= SORT_REGULAR ] )
<?php
$fruits = array("lemon", "orange", "banana", "apple");
sort($fruits);
var_dump($fruits);
?>
结果:
array
0 =>
string
"apple" (length=5)
1 =>
string
"banana" (length=6)
2 =>
string
"lemon" (length=5)
3 =>
string
"orange" (length=6)
--------------------rsort降序排列--------------------
复制代码 代码如下:
<?php
$fruits = array("lemon", "orange", "banana", "apple");
rsort($fruits);
var_dump($fruits);
?>
结果:
array
0 =>
string
"orange" (length=6)
1 =>
string
"lemon" (length=5)
2 =>
string
"banana" (length=6)
3 =>
string
"apple" (length=5)
---------------asort按照二维数组值的升序排列(保持key=>value的关联关系)-----------
复制代码 代码如下:
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
asort($fruits);
var_dump($fruits);
?>
结果:
array
"c" =>
string
"apple" (length=5)
"b" =>
string
"banana" (length=6)
"d" =>
string
"lemon" (length=5)
"a" =>
string
"orange" (length=6)
---------arsort按照二维数组值的降序排列(保持key=>value的关联关系)---------
复制代码 代码如下:
<?php
$fruits = array("d" => "lemon", "a" => "orange", "b" => "banana", "c" => "apple");
arsort($fruits);
var_dump($fruits);
?>
结果
array
"a" =>
string
"orange" (length=6)
"d" =>
string
"lemon" (length=5)
"b" =>
string
"banana" (length=6)
"c" =>
string
"apple" (length=5)
--------------------ksort按照数组的key升序排列--------------
复制代码 代码如下:
<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
ksort($fruits);
var_dump($fruits);
?>
结果
array
"a" =>
string
"orange" (length=6)
"b" =>
string
"banana" (length=6)
"c" =>
string
"apple" (length=5)
"d" =>
string
"lemon" (length=5)
---------------------krsort按照数组key的降序排列-----------------------
复制代码 代码如下:
<?php
$fruits = array("d"=>"lemon", "a"=>"orange", "b"=>"banana", "c"=>"apple");
krsort($fruits);
var_dump($fruits);
?>
array
"d" =>
string
"lemon" (length=5)
"c" =>
string
"apple" (length=5)
"b" =>
string
"banana" (length=6)
"a" =>
string
"orange" (length=6)
----------------usort函数按照用户自定义的函数排序----------------
复制代码 代码如下:
<?php
function cmp($a, $b)
{
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
$a = array(3, 2, 5, 6, 1);
usort($a, "cmp");
var_dump($a);
?>
结果:
array
0 =>
int
1
1 =>
int
2
2 =>
int
3
3 =>
int
5
4 =>
int
6
-----------------uksort使用自定义函数按照数组的key排序-----------------
复制代码 代码如下:
<?php
function cmp($a, $b)
{
$a = preg_replace("@^(a|an|the) @", "", $a);
$b = preg_replace("@^(a|an|the) @", "", $b);
return strcasecmp($a, $b);
}
$a = array("John" => 1, "the Earth" => 2, "an apple" => 3, "a banana" => 4);
uksort($a, "cmp");
var_dump($a);
?>
结果:
array
"an apple" =>
int
3
"a banana" =>
int
4
"the Earth" =>
int
2
"John" =>
int
1
--------------uasort将数组用自定义函数按照value排序,保持索引关系不变---------
复制代码 代码如下:
<?php
// Comparison function
function cmp($a, $b) {
if ($a == $b) {
return 0;
}
return ($a < $b) ? -1 : 1;
}
// Array to be sorted
$array = array("a" => 4, "b" => 8, "c" => -1, "d" => -9, "e" => 2, "f" => 5, "g" => 3, "h" => -4);
var_dump($array);
// Sort and print the resulting array
uasort($array, "cmp");
var_dump($array);
?>
结果:
array
"a" =>
int
4
"b" =>
int
8
"c" =>
int
-1
"d" =>
int
-9
"e" =>
int
2
"f" =>
int
5
"g" =>
int
3
"h" =>
int
-4
array
"d" =>
int
-9
"h" =>
int
-4
"c" =>
int
-1
"e" =>
int
2
"g" =>
int
3
"a" =>
int
4
"f" =>
int
5
"b" =>
int
8
-------------------array_multisort排序多个数组或多维数组---------
复制代码 代码如下:
<?php
$ar = array(
array("10", 11, 100, 100, "a"),
array( 1, 2, "2", 3, 1)
);array_multisort($ar[0], SORT_ASC, SORT_STRING,
$ar[1], SORT_NUMERIC, SORT_DESC);
var_dump($ar);
?>
结果:
array
0 =>
array
0 =>
string
"10" (length=2)
1 =>
int
100
2 =>
int
100
3 =>
int
11
4 =>
string
"a" (length=1)
1 =>
array
0 =>
int
1
1 =>
int
3
2 =>
string
"2" (length=1)
3 =>
int
2
4 =>
int
1
//说明:
1 上例中:$ar数组优先按照$ar[0]的字符串值升序排列,如果字符串值相等,再按照$ar[1]数组的数字值降序排列。
2 array_multisort函数的任意一个位置的参数如果是数组,表示排序时用的值,
如果有多个数组参数,优先按照前边的数组值进行排序,如果是常量,例如
SORT_ASC, SORT_DESC, SORT_REGULAR,SORT_NUMERIC, SORT_STRING.
表示排序方法(数组取值前优先)。
==========================================================================================
PHP二维数组排序函数
PHP一维数组的排序可以用sort(),asort(),arsort()等函数,但是PHP二维数组的排序需要自定义。
以下函数是对一个给定的二维数组按照指定的键值进行排序,先看函数定义:
复制代码 代码如下:
function array_sort($arr,$keys,$type="asc"){
$keysvalue = $new_array = array();
foreach ($arr as $k=>$v){
$keysvalue[$k] = $v[$keys];
}
if($type == "asc"){
asort($keysvalue);
}else{
arsort($keysvalue);
}
reset($keysvalue);
foreach ($keysvalue as $k=>$v){
$new_array[$k] = $arr[$k];
}
return $new_array;
}
它可以对二维数组按照指定的键值进行排序,也可以指定升序或降序排序法(默认为升序),用法示例:
复制代码 代码如下:
$array = array(
array("name"=>"手机","brand"=>"诺基亚","price"=>1050),
array("name"=>"笔记本电脑","brand"=>"lenovo","price"=>4300),
array("name"=>"剃须刀","brand"=>"飞利浦","price"=>3100),
array("name"=>"跑步机","brand"=>"三和松石","price"=>4900),
array("name"=>"手表","brand"=>"卡西欧","price"=>960),
array("name"=>"液晶电视","brand"=>"索尼","price"=>6299),
array("name"=>"激光打印机","brand"=>"惠普","price"=>1200)
);
$ShoppingList = array_sort($array,"price");
print_r($ShoppingList);
上面是对$array这个二维数组按照"price"从低到高的排序。
输出结果:(略)。