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

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

高洛峰
高洛峰Original
2016-12-30 11:00:181606browse

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.

For more examples of commonly used array array functions in PHP [assignment, splitting, merging, calculating, adding, deleting, querying, judging, sorting] please pay attention to the PHP Chinese website for related articles!

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