PHP commonly used arrays Array Function Example Summary "assignment, split, merge, calculate, add, delete, query, judge, sort" _php tips

The example of this article summarizes the common PHP array function. Share to everyone for your reference, specific 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 ("One", "two", "three");
$c = Array_combine ($a, $b);
Print_r ($c);
/** results
*array ([one] => [two] => two [three] => III)
* *

Array_chunk

Function: Split fractions to form multiple arrays

<?php
$input _array = Array ("A" => "Apple", "B" => "Blue", "C", "D", "E");
echo "<pre>";
Print_r (Array_chunk ($input _array, 2));
Print_r (Array_chunk ($input _array, 2,true));
echo "</pre>";
/** result
Array
(
 [0] => array
  (
   [0] => Apple
   [1] => blue
  )
 [1] => array< c15/> (
   [0] => C
   [1] => D
  )
 [2] => Array
  (
   [0] => e
  )
)
array< c25/> (
 [0] => array
  (
   [a] => Apple
   [b] => blue
  )
 [1] => array
  (
   [0 ] => c
   [1] => D
  )
 [2] => Array
  (
   [2] => e
  )
)
* *

Array_count_values

Function: Count the number of occurrences of a value in an array

<?php
$input _array = Array ("A" => "Apple", "B" => "Blue", "C", "D", "E");
echo "<pre>";
Print_r (Array_count_values ($input _array));
echo "</pre>";
/** result
Array
(
 [Apple] => 1
 [blue] => 1
 [c] => 1
 [d] => 1
 [E] => 1
)
*/

Array_diff

Function: Remove the data from the second array in the first array, and return the remainder as the result

<?php
$array 1 = Array ("A" => "Apple", "B" => "Blue", "C", "D", "E");
$array 2 = Array ("Apple", "C", "D", "F");
$result = Array_diff ($array 1, $array 2);
$result 2 = Array_diff ($array 2, $array 1);
echo "<pre>";
Print_r ($result);//array 1 removes the remaining
Print_r ($result 2) from array 2;//array 2 to remove the remaining
echo "</pre>" in array 1;
/** result
Array
(
 [b] => blue
 [2] => e
)
array
(
 [3] => f
)
* /

Array_map

Function: Executes the callback function into the array

<?php
//defines the callback functions function
cube ($n) {return
 ($n * $n * $n);
}
$a = array (1,2,3,4,5);
$b = Array_map ("cube", $a);
echo "<pre>";
Print_r ($b);
echo "</pre>";
/** result
Array
(
 [0] => 1
 [1] => 8
 [2] =>
 [3] =>
 [4] =>
) c42/>*/

Array_merge

Function: Merge one or more arrays

Note: If the following key name will overwrite the previous content, the key number will be added to the back

<?php
$array 1 = Array ("Color" => "red", 2,4);
$array 2 = Array ("A", "B", "Color" => "green", "shape" => "trapezoid", 4);
$result 1 = array_merge ($array 1, $array 2);
$result 2 = array_merge_recursive ($array 1, $array 2);
echo "<pre>";
Print_r ($result 1);
Print_r ($result 2);
echo "</pre>";
/** result
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 element content that was excluded

<?php
$stack = Array ("Orange", "banana", "apple", "1");
$last = Array_pop ($stack);
echo "<pre>";
Print_r ($stack);
Print_r ($last);
echo "</pre>";
/** result
Array
(
 [0] => Orange
 [1] => banana
 [2] => Apple
)
1
*

Array_push

Function: Presses a plurality of cells into the end of the array, returns the number of arrays after

<?php
$stack = Array ("Orange", "banana");
$count = Array_push ($stack, "Apple", "Red", "Blue");
echo "<pre>";
Print_r ($stack);
Print_r ($count);
echo "</pre>";
/** result
Array
(
 [0] => Orange
 [1] => banana
 [2] => Apple
 [3] => red
 [4] =& Gt 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);
/** result
Array
(
 [0] => 1
 [1] => 4
)
array
(
 [0] => 0
 [1] => 1
 [2] => 3
)
*/

Array_search

Function: Query the contents of the array, return the key value, if there are more than one match, return the first matching content

<?php
$array = Array ("Blue" => "B", "Red" => "R", "Green", "R");
$key = Array_search (' B ', $array);
echo $key;
echo "<br>";
$key = Array_search (' R ', $array);
echo $key;
echo "<br>";
/** results
Blue
Red
* *

Array_shift

Function: Remove the beginning element, contrary to Array_pop

<?php
$fruit = Array ("Milk", "orange", "banana", "apple");
$top = Array_shift ($fruit);
Print_r ($top);
echo "<br>";
Print_r ($fruit);
/** results
Milk
Array ([0] => Orange [1] => banana [2] => apple)
* *

Array_unique

Function: Remove the elements that are duplicated in the array, preserving the first occurrence, including the 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);
/** result
Array ([a] => green [0] => red [1] => Blue)
Array ([a] => green [0] => Red [b] => GRE En [1] => blue [C] => red)
* *

Array_slice

Function: Remove part of an element from an array

<?php
$input = Array ("A", "B", "C", "D", "E");
$output = Array_slice ($input, 2);//When the second argument is not, the representation is taken to the last element
Print_r ($output);
echo "<br>";
$output = Array_slice ($input, -2,1);//When the second argument is positive, the number is represented; the first is 1, and the second is -2
print_r ($output);
echo "<br>";
$output = Array_slice ($input, 0,3);
Print_r ($output);
echo "<br>";
$output = Array_slice ($input, 2,-1);//The second parameter is a negative number, which is the position, which is taken, not including itself
Print_r ($output);
echo "<br>";
$output = Array_slice ($input, 2,-1,true);//When the third argument is true, the original key value
Print_r ($output) is preserved;
echo "<br>";
/** result
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: Returns the number of elements in an array.

<?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;
/** Results
4
5
* *

Current

Function: Gets the current pointer to the element

<?php
$array = Array ("Foot", "bike", "car", "plane");
$result = current ($array);
echo $result. " <br> ";
Next ($array);//make pointer to next element
$result = current ($array);
echo $result. " <br> ";
Prev ($array);//Make the pointer point to the previous element
$result = current ($array);
echo $result. " <br> ";
End ($array);//Make the pointer point to the last element
$result = current ($array);
echo $result. " <br> ";
/** results
foot
bike
foot
plane
* *

In_array

Function: Verifies that a value exists in an array, returns TRUE, does not return false

<?php
$os _list = Array ("Mac", "NT", "Irix", "Linux");
if (In_array ("Irix", $os _list)) {
 echo "exists Irix in the current operating system list";
} else{
 echo "does not exist in the current operating system list Irix";
}
echo "<br>";
if (In_array ("Mac", $os _list)) {
 echo "Mac" exists in the current operating system list;
} else{
 echo "Mac" does not exist in the current operating system list;
}
echo "<br>";
/** results
The current operating system list exists IRIX the
current operating system does not exist in the list of Mac
* *

List

function: Assigning information in an array 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>";
/** results
red,blue,green
red,green
Green
* *

Shuffle

Features: Scrambling arrays

<?php
$numbers = range (1,5);//Generate a random array
print_r ($numbers);
echo "<br/>";
Shuffle ($numbers);//Disturb array
print_r ($numbers);
/** result
Array ([0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 5)
Array ([0] => 4 [1] => 1 [2] =& Gt 5 [3] => 2 [4] => 3)
* *

Array_keys

Function: Gets the key name of the array, and the second parameter can specify that an element be fetched

<?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>";
/** result
Array ([0] => 0 [1] => color)
Array ([0] => 0 [1] => 3 [2] => 4)
Array ([0] => Color [1] => size)
* *

Array_reverse

Function: Gets the inverse of the array

<?php
$input = Array ("PHP", 3.0,array ("Green", "red"));
$result = Array_reverse ($input); Upset key name
$result _keyed = Array_reverse ($input, TRUE);//reserve Key
name Print_r ($result);
Print_r ($result _keyed);
/** result
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 sort, index unchanged

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => "Apple",
 );
Arsort ($fruits);//reverse-sort by character or digital
foreach ($fruits as $key => $val) {
 echo $key = $val <br>;
}
/** result
B = orange
a = lemon
c = Banana
d = Apple
* *

Asort

Function: Perform forward sort

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => " Apple ",
 );
Arsort ($fruits);//reverse-sort by character or digital
foreach ($fruits as $key => $val) {
 echo $key = $val <br>;
}
echo "<p>";
Asort ($fruits)//by Word single-character to sort or numerically
foreach ($fruits as $key => $val) {
 echo $key = $val <br>;
}
/** result
B = orange
a = lemon
c = Banana
d = Apple
d = apple
c = Banana
a = lemon
B = Orange
* *

Krsort

Function: Reverse sort according to key name

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => "Apple",
 );
Krsort ($fruits);//In reverse order by key name or number
foreach ($fruits as $key => $val) {
 echo "$key = $val <br>";
}
/** result
d = apple
c = Banana
B = orange
a = lemon
* *

Ksort

Function: Forward sort according to key name

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => " Apple ",
 );
Ksort ($fruits)//By the key name forward sort or number
foreach ($fruits as $key => $val) {
 echo $key = $val <br>;
}
/** result
a = lemon
b = orange
c = Banana
d = Apple
* *

Rsort

Function: Reverse sort by value, key name change

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => "Apple",
 );
Rsort ($fruits);//In reverse order or number by value, the key name changes
foreach ($fruits as $key => $val) {
 echo "$key = $val <br>";
}
/** result
0 = orange
1 = lemon
2 = Banana
3 = Apple
* *

Sort

Function: Forward sort by value, key name changed

<?php
$fruits = Array (
 "a" => "lemon",
 "B" => "Orange",
 "C" => "banana",
 "D" => " Apple ",
 );
Sort ($fruits);//In reverse order or number by value, the key name changes
foreach ($fruits as $key => $val) {
 echo "$key = $val <br>";
}
/** result
0 = Apple
1 = banana
2 = lemon
3 = Orange
* *

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