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 PHP Script Tips - PHP Built-in Functions for Arrays Home >> FAQs/Tutorials >> PHP Script
Tutorials and Tips >> Index PHP Script Tips -
PHP Built-in Functions for Arrays By: FYICenter.com Part:   1  
2  3  4  5  6  7  A collection of 19 tips on PHP
functions on arrays. Clear answers are provided with tutorial exercises on
searching keys and values, sorting arrays, merging two arrays, looping on
array elements, expanding and truncating arrays. Topics included in this
collection are: How To Get the Total Number of Values in an Array? How Do
You If a Key Is Defined in an Array? How To Find a Specific Value in an
Array? How To Get All the Keys Out of an Array? How To Get All the Values
Out of an Array? How To Sort an Array by Keys? How To Sort an Array by
Values? How To Join a List of Keys with a List of Values into an Array?
How To Merge Values of Two Arrays into a Single Array? How To Use an Array
as a Queue? How To Use an Array as a Stack? How To Randomly Retrieve a
Value from an Array? How To Loop through an Array without Using "foreach"?
How To Create an Array with a Sequence of Integers or Characters? How To
Pad an Array with the Same Value Multiple Times? How To Truncate an Array?
How To Join Multiple Strings Stored in an Array into a Single String? How
To Split a String into an Array of Substring? How To Get the Minimum or
Maximum Value of an Array? How To Get the Total Number of Values in an
Array? You can get the total number of values in an array by using the
count() function. Here is a PHP example script: <?php $array =
array("PHP", "Perl", "Java"); print_r("Size 1: ".count($array)."\n");
$array = array(); print_r("Size 2: ".count($array)."\n"); ?> This
script will print: Size 1: 3 Size 2: 0 Note that count() has an alias
called sizeof(). How Do You If a Key Is Defined in an Array? There are two
functions can be used to test if a key is defined in an array or not:
array_key_exists($key, $array) - Returns true if the $key is defined in
$array. isset($array[$key]) - Returns true if the $key is defined in
$array. Here is a PHP example script: <?php $array =
array("Zero"=>"PHP", "One"=>"Perl", "Two"=>"Java"); print("Is
'One' defined? ".array_key_exists("One", $array)."\n"); print("Is '1'
defined? ".array_key_exists("1", $array)."\n"); print("Is 'Two' defined?
".isset($array["Two"])."\n"); print("Is '2' defined?
".isset($array[2])."\n"); ?> This script will print: Is 'One' defined?
1 Is '1' defined? Is 'Two' defined? 1 Is '2' defined? How To Find a
Specific Value in an Array? There are two functions can be used to test if
a value is defined in an array or not: array_search($value, $array) -
Returns the first key of the matching value in the array, if found.
Otherwise, it returns false. in_array($value, $array) - Returns true if
the $value is defined in $array. Here is a PHP script on how to use
arrary_search(): <?php $array = array("Perl", "PHP", "Java", "PHP");
print("Search 1: ".array_search("PHP",$array)."\n"); print("Search 2:
".array_search("Perl",$array)."\n"); print("Search 3:
".array_search("C#",$array)."\n"); print("\n"); ?> This script will
print: Search 1: 1 Search 2: 0 Search 3: How To Get All the Keys Out of an
Array? Function array_keys() returns a new array that contains all the keys
of a given array. Here is a PHP script on how to use array_keys(): <?php
$mixed = array(); $mixed["Zero"] = "PHP"; $mixed[1] = "Perl"; $mixed["Two"]
= "Java"; $mixed["3"] = "C+"; $mixed[""] = "Basic"; $mixed[] = "Pascal";
$mixed[] = "FORTRAN"; $keys = array_keys($mixed); print("Keys of the input
array:\n"); print_r($keys); ?> This script will print: Keys of the input
array: Array ( [0] => Zero [1] => 1 [2] => Two [3] => 3 [4] => [5] => 4 [6]
=> 5 ) (Continued on next part...) Part:   1   2  3  4  5  6  7  Selected Developer Jobs: More...