Use the array function in PHP to create an array _php instance

The array in PHP is actually an ordered map. A mapping is a type that associates values to the keys. This type is optimized in many ways, so you can think of it as a real array, or a list (vector), a hash list (an implementation of a map), a dictionary, a collection, a stack, a queue, and more possibilities. Because the value of an array element can also be another array, a tree structure and a multidimensional array are allowed.

Array

(PHP 4, PHP 5)

array-Create a new array

Description

Copy Code code as follows:

Array array ([mixed $ ...])

Returns an array created from a parameter. Parameters can be indexed using the => operator. For information about what the array is, read the section of the array.

Note:

Array () is a language structure that literally represents an array, not a regular function.

Syntax "Index => values", separated by commas, defines indexes and values. An index can be a string or a number. If an index is omitted, an integer index starting at 0 is automatically generated. If the index is an integer, the next resulting index will be the current largest integer index + 1. Note If two identical indexes are defined, the latter one overwrites the previous one.

Adding a comma after the last defined array item is not uncommon, but is a legitimate syntax.

The following example shows how to create a two-dimensional array, assign a key name to the corresponding array, and skip and continue the numeric index in the normal array.

Example #1 Array () example

<?php
$fruits = Array (
  "fruits" => Array ("A" => "Orange", "B" => "banana", "C" => "Apple"),
  "n Umbers "=> Array (1, 2, 3, 4, 5, 6),
  " holes "  => Array (" A ", 5 =>" second "," third ")
);
? >

Automatic indexing of Example #2 Array ()

<?php
$array = Array (1, 1, 1, 1, 1, 8 => 1, 4 => 1, 3 =>);
Print_r ($array);
? >

The above routines will output:

Array
(
[0] => 1
[1] => 1
[2] => 1
[3] => 13
[4] => 1
[8] => 1
[9] => 19
)

Note that index 3 is defined two times and retains the last value of 13. Index 4 is defined after index 8, and the next auto-generated index (with a value of 19) is 9, because the largest index is 8.

This example establishes an array starting with 1.

Example #3 Array () indexed starting at 1

<?php
$firstquarter = Array (1 => ' January ', ' February ', ' March ');
Print_r ($firstquarter);
? >

The above routines will output:

 Array
(
  [1] => January
  [2] => February
  [3] => March
)

In Perl, you can access the values of an array in double quotes. But in PHP you need to enclose the array in curly braces.

Example #4 access to an array within double quotes

<?php
$foo = Array (' Bar ' => ' Baz ');
echo "Hello {$foo [' Bar ']}!];" Hello baz!
? >

PHP Array function

PHP: Indicates the earliest version of PHP that supports this function.

function	Description	PHP
Array ()	Creates an array.	3
Array_change_key_case ()	Returns an array whose keys are either uppercase or lowercase.	4
Array_chunk ()	Divides an array into a new array block.	4
Array_combine ()	Creates a new array by merging two arrays.	5
Array_count_values ()	Used to count the occurrences of all values in an array.	4
Array_diff ()	Returns an array of difference sets for two arrays.	4
ARRAY_DIFF_ASSOC ()	Compares the key name and key values and returns an array of difference sets for two arrays.	4
Array_diff_key ()	Compares the key name and returns an array of difference sets for two arrays.	5
ARRAY_DIFF_UASSOC ()	Computes the difference set of an array by indexing the user-supplied callback function.	5
Array_diff_ukey ()	Compares the difference set of an array with a callback function for the key name.	5
Array_fill ()	Fills the array with the given value.	4
Array_filter ()	Filters the elements in an array with a callback function.	4
Array_flip ()	Swap the keys and values in the array.	4
Array_intersect ()	Computes the intersection of an array.	4
ARRAY_INTERSECT_ASSOC ()	Compares the key name and key values and returns an array of intersections of two arrays.	4
Array_intersect_key ()	Computes the intersection of an array by using the key name comparison.	5
ARRAY_INTERSECT_UASSOC ()	Computes the intersection of an array with an index check and compares the index with a callback function.	5
Array_intersect_ukey ()	Computes the intersection of the array using the callback function to compare the key name.	5
Array_key_exists ()	Checks whether the given key name or index exists in the array.	4
Array_keys ()	Returns all the key names in the array.	4
Array_map ()	The callback function is acting on the cell of the given array.	4
Array_merge ()	Merges one or more arrays into an array.	4
Array_merge_recursive ()	Recursively merge one or more arrays.	4
Array_multisort ()	Sorts multiple arrays or multidimensional arrays.	4
Array_pad ()	Fills an array with a value to a specified length.	4
Array_pop ()	Eject the last cell of the array (out of the stack).	4
Array_product ()	Calculates the product of all the values in an array.	5
Array_push ()	Presses one or more units (elements) into the end of the array (into the stack).	4
Array_rand ()	Randomly selects one or more elements from an array and returns.	4
Array_reduce ()	Iteratively simplifies the array to a single value using the callback function.	4
Array_reverse ()	Flips the order of elements in the original array, creates a new array, and returns.	4
Array_search ()	Searches the array for a given value, and returns the corresponding key name if successful.	4
Array_shift ()	Deletes the first element in the array and returns the value of the deleted element.	4
Array_slice ()	Takes a value out of a condition in an array and returns it.	4
Array_splice ()	Remove a portion of the array and replace it with other values.	4
Array_sum ()	Calculates the and of all the values in the array.	4
Array_udiff ()	Use the callback function to compare data to compute the difference set of an array.	5
ARRAY_UDIFF_ASSOC ()	Calculates the difference set of an array with an index check and compares the data with a callback function.	5
ARRAY_UDIFF_UASSOC ()	Calculates the difference set of an array with an index check and compares the data and index with the callback function.	5
Array_uintersect ()	Computes the intersection of the array and compares the data with the callback function.	5
ARRAY_UINTERSECT_ASSOC ()	Computes the intersection of the array with the index check and compares the data with the callback function.	5
ARRAY_UINTERSECT_UASSOC ()	Computes the intersection of the array with the index check and compares the data and index with the callback function.	5
Array_unique ()	Deletes the duplicate value in the array.	4
Array_unshift ()	Inserts one or more elements at the beginning of the array.	4
Array_values ()	Returns all the values in the array.	4
Array_walk ()	Apply a user function to each member in the array.	3
Array_walk_recursive ()	Each member of an array applies a user function recursively.	5
Arsort ()	Reverse-Sort the array and keep the index relationship.	3
Asort ()	The array is sorted and the index relationship is maintained.	3
Compact ()	Create an array that includes the variable names and their values.	4
Count ()	Calculates the number of elements in an array or the number of attributes in an object.	3
Current ()	Returns the current element in an array.	3
each ()	Returns the current key/value pair in the array and moves the array pointer one step forward.	3
End ()	Points the array's internal pointer to the last element.	3
Extract ()	Imports a variable from an array into the current symbol table.	3
In_array ()	Checks whether the specified value exists in the array.	4
Key ()	Gets the key name from the associative array.	3
Krsort ()	The arrays are sorted in reverse order by key names.	3
Ksort ()	The array is sorted by key name.	3
List ()	Assign the values in the array to some variables.	3
Natcasesort ()	Use the "natural sort" algorithm to sort the case-insensitive letters of the array.	4
Natsort ()	Sort the array using the natural sort algorithm.	4
Next ()	Moves the internal pointer in the array forward one bit.	3
POS ()	The alias for current ().	3
Prev ()	Returns the internal pointer of an array to a bit.	3
Range ()	Creates an array that contains the elements of the specified range.	3
Reset ()	Points the array's internal pointer to the first element.	3
Rsort ()	Reverse-Sort the array.	3
Shuffle ()	Rearrange the elements in the array in random order.	3
sizeof ()	The alias for Count ().	3
Sort ()	Sort the array.	3
Uasort ()	Use the user-defined comparison function to sort the values in the array and keep the index associated.	3
Uksort ()	Use the user-defined comparison function to sort the key names in the array.	3
Usort ()	Use the user-defined comparison function to sort the values in the array.	3