Summary of examples of commonly used array array functions in PHP [assignment, splitting, merging, calculation, adding, deleting, querying, judging, sorting]

The examples in this article summarize the commonly used array array functions in PHP. Share it with everyone for your reference, the details are as follows:

array_combine

Function: Use the value of one array as the key name of the new array, and the value of the other array as the value of the new array

Case:

<?php
$a = array("one","two","three");
$b = array("一","二","三");
$c = array_combine($a,$b);
print_r($c);
/**结果
*Array ( [one] => 一 [two] => 二 [three] => 三 )
*/

array_chunk

Function: split the array into multiple arrays

<?php
$input_array = array("a"=>"apple","b"=>"blue","c","d","e");
echo "<pre class="brush:php;toolbar:false">";
print_r(array_chunk($input_array, 2));
print_r(array_chunk($input_array, 2,True));
echo "

"; /**结果 Array ( [0] => Array ( [0] => apple [1] => blue ) [1] => Array ( [0] => c [1] => d ) [2] => Array ( [0] => e ) ) Array ( [0] => Array ( [a] => apple [b] => blue ) [1] => Array ( [0] => c [1] => d ) [2] => Array ( [2] => e ) ) */

array_count_values

Function: Count the number of times a value appears in an array

<?php
$input_array = array("a"=>"apple","b"=>"blue","c","d","e");
echo "<pre class="brush:php;toolbar:false">";
print_r(array_count_values($input_array));
echo "

"; /**结果 Array ( [apple] => 1 [blue] => 1 [c] => 1 [d] => 1 [e] => 1 ) */

array_diff

Function: Remove the data in the second array from the first array and return the remaining content as the result

<?php
$array1 = array("a"=>"apple","b"=>"blue","c","d","e");
$array2 = array("apple","c","d","f");
$result = array_diff($array1, $array2);
$result2 = array_diff($array2, $array1);
echo "<pre class="brush:php;toolbar:false">";
print_r($result);//数组1中去掉数组2中剩下的
print_r($result2);//数组2中去掉数组1中剩下的
echo "

"; /**结果 Array ( [b] => blue [2] => e ) Array ( [3] => f ) */

array_map

Function: Execute the callback function into the array

<?php
//定义回调函数
function cube($n){
 return ($n*$n*$n);
}
$a = array(1,2,3,4,5);
$b = array_map("cube",$a);
echo "<pre class="brush:php;toolbar:false">";
print_r($b);
echo "

"; /**结果 Array ( [0] => 1 [1] => 8 [2] => 27 [3] => 64 [4] => 125 ) */

array_merge

Function: Merge one or more arrays

Note: If there are keys with the same key names at the back, the previous content will be overwritten, and the key names with numbers will be added to the back

<?php
$array1 = array("color"=>"red",2,4);
$array2 = array("a","b","color"=>"green","shape"=>"trapezoid",4);
$result1 = array_merge($array1,$array2);
$result2 = array_merge_recursive($array1,$array2);
echo "<pre class="brush:php;toolbar:false">";
print_r($result1);
print_r($result2);
echo "

"; /**结果 Array ( [color] => green [0] => 2 [1] => 4 [2] => a [3] => b [shape] => trapezoid [4] => 4 ) Array ( [color] => Array ( [0] => red [1] => green ) [0] => 2 [1] => 4 [2] => a [3] => b [shape] => trapezoid [4] => 4 ) */

array_pop

Function: Remove the last element of the array and return the content of the removed element

<?php
$stack = array("orange","banana","apple","1");
$last = array_pop($stack);
echo "<pre class="brush:php;toolbar:false">";
print_r($stack);
print_r($last);
echo "

"; /**结果 Array ( [0] => orange [1] => banana [2] => apple ) 1 */

array_push

Function: Push multiple units into At the end of the array, return the number of arrays after

<?php
$stack = array("orange","banana");
$count = array_push($stack,"apple","red","blue");
echo "<pre class="brush:php;toolbar:false">";
print_r($stack);
print_r($count);
echo "

"; /**结果 Array ( [0] => orange [1] => banana [2] => apple [3] => red [4] => blue ) 5 */

array_rand

Function: Get a random key name

<?php
$input = array("orange","banana","apple","red","blue");
$rand = array_rand($input,2);;
print_r($rand);
$rand = array_rand($input,3);
print_r($rand);
/**结果
Array
(
 [0] => 1
 [1] => 4
)
Array
(
 [0] => 0
 [1] => 1
 [2] => 3
)
*/

array_search

Function: Query the content in the array and return the key value. If there are multiple matches, return the first matching content

<?php
$array = array("blue"=>"b","red"=>"r","green","r");
$key = array_search(&#39;b&#39;, $array);
echo $key;
echo "<br>";
$key = array_search(&#39;r&#39;, $array);
echo $key;
echo "<br>";
/**结果
blue
red
*/

array_shift

Function: Remove the starting elements, opposite to array_pop

<?php
$fruit = array("milk","orange","banana","apple");
$top = array_shift($fruit);
print_r($top);
echo "<br>";
print_r($fruit);
/**结果
milk
Array ( [0] => orange [1] => banana [2] => apple )
*/

array_unique

Function: Remove duplicate elements from the array and retain the first one, including key name and value

<?php
$input = array("a"=>"green","red","b"=>"green","blue","c"=>"red");
$result = array_unique($input);
print_r($result);
echo "<br>";
print_r($input);
/**结果
Array ( [a] => green [0] => red [1] => blue )
Array ( [a] => green [0] => red [b] => green [1] => blue [c] => red )
*/

array_slice

Function: From the array Take out some elements

<?php
$input = array("a","b","c","d","e");
$output = array_slice($input,2);//第二个参数没有时，表示取到最后一个元素
print_r($output);
echo "<br>";
$output = array_slice($input,-2,1);//第二个参数是正数时，表示个数；倒数第一个是-1，倒数第二个是-2
print_r($output);
echo "<br>";
$output = array_slice($input,0,3);
print_r($output);
echo "<br>";
$output = array_slice($input,2,-1);//第二个参数是负数时，表示位置，取到哪一位，不包括本身
print_r($output);
echo "<br>";
$output = array_slice($input,2,-1,true);//第三个参数为true时，保留原有的键值
print_r($output);
echo "<br>";
/**结果
Array ( [0] => c [1] => d [2] => e )
Array ( [0] => d )
Array ( [0] => a [1] => b [2] => c )
Array ( [0] => c [1] => d )
Array ( [2] => c [3] => d )
*/

count

Function: Return the number of array elements. If the element is an array, it is counted as one

<?php
$input = array("a","b","c",array("d","e"));
$count = count($input);
echo $count;
echo "<br>";
$input = array("a","b","c","d","e");
$count = count($input);
echo $count;
/**结果
4
5
*/

current

Function: Get the current pointer pointing to the element

<?php
$array = array("foot","bike","car","plane");
$result = current($array);
echo $result."<br>";
next($array);//使指针指向下一个元素
$result = current($array);
echo $result."<br>";
prev($array);//使指针指向前一个元素
$result = current($array);
echo $result."<br>";
end($array);//使指针指向最后一个元素
$result = current($array);
echo $result."<br>";
/**结果
foot
bike
foot
plane
*/

in_array

Function: Check whether a certain value exists in the array, return True if not, return False

<?php
$os_list = array("Mac","NT","Irix","Linux");
if(in_array("Irix",$os_list)){
 echo "当前操作系统列表中存在Irix";
}else{
 echo "当前操作系统列表中不存在Irix";
}
echo "<br>";
if(in_array("mac",$os_list)){
 echo "当前操作系统列表中存在mac";
}else{
 echo "当前操作系统列表中不存在mac";
}
echo "<br>";
/**结果
当前操作系统列表中存在Irix
当前操作系统列表中不存在mac
*/

list

Function: convert the array Assign the information in to multiple variables

<?php
$info = array("red","blue","green");
list($flag,$sky,$grassland) = $info;
echo "$flag,$sky,$grassland";
echo "<br>";
list($flag,,$grassland) = $info;
echo "$flag,$grassland";
echo "<br>";
list(,,$grassland) = $info;
echo "$grassland";
echo "<br>";
/**结果
red,blue,green
red,green
green
*/

shuffle

Function: shuffle the array

<?php
$numbers = range(1,5);//生成一个随机数组
print_r($numbers);
echo "<br/>";
shuffle($numbers);//打乱数组
print_r($numbers);
/**结果
Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5 )
Array ( [0] => 4 [1] => 1 [2] => 5 [3] => 2 [4] => 3 )
*/

array_keys

Function: Get the key name of the array, the second parameter can specify to get an element

<?php
$array = array(0=>100,"color"=>"red");
print_r(array_keys($array));
echo "<br>";
$array = array("blue","red","green","blue","blue");
print_r(array_keys($array,"blue"));
echo "<br>";
$array = array("color"=>array("blue","red","green"),"size"=>array("small","medium","large"));
print_r(array_keys($array));
echo "<br>";
/**结果
Array ( [0] => 0 [1] => color )
Array ( [0] => 0 [1] => 3 [2] => 4 )
Array ( [0] => color [1] => size )
*/

array_reverse

Function: Get the reverse of the array

<?php
$input = array("php",3.0,array("green","red"));
$result = array_reverse($input); //打乱键名
$result_keyed = array_reverse($input,TRUE);//保留键名
print_r($result);
print_r($result_keyed);
/**结果
Array
(
 [0] => Array
  (
   [0] => green
   [1] => red
  )
 [1] => 3
 [2] => php
)
Array
(
 [2] => Array
  (
   [0] => green
   [1] => red
  )
 [1] => 3
 [0] => php
)
*/

arsort

Function: Reverse sorting, the index remains unchanged

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
arsort($fruits);//按照字符逆向排序或数字
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
b = orange
a = lemon
c = banana
d = apple
*/

##asort

Function: Forward sorting

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
arsort($fruits);//按照字符逆向排序或数字
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
echo "<p>";
asort($fruits);//按照字符正向排序或数字
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
b = orange
a = lemon
c = banana
d = apple
d = apple
c = banana
a = lemon
b = orange
*/

krsort

Function: Reverse sorting by key name

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
krsort($fruits);//按照键名逆向排序或数字
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
d = apple
c = banana
b = orange
a = lemon
*/

ksort

Function: Forward sorting by key name

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
ksort($fruits);//按照键名正向排序或数字
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
a = lemon
b = orange
c = banana
d = apple
*/

rsort

Function: reverse sorting by value, key name change

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
rsort($fruits);//按照值进行逆向排序或数字，键名改变
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
0 = orange
1 = lemon
2 = banana
3 = apple
*/

sort

Function: Forward sorting by value, key name change

<?php
$fruits = array(
 "a"=>"lemon",
 "b"=>"orange",
 "c"=>"banana",
 "d"=>"apple",
 );
sort($fruits);//按照值进行逆向排序或数字，键名改变
foreach($fruits as $key=>$val){
 echo "$key = $val<br>";
}
/**结果
0 = apple
1 = banana
2 = lemon
3 = orange
*/

I hope this article will help everyone in PHP programming design help.

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