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 |