Appending One Array to Another in PHP

By: David Sklar Emailed: 1729 times Printed: 2329 times    

Latest comments
By: rohit kumar - how this program is work
By: Kirti - Hi..thx for the hadoop in
By: Spijker - I have altered the code a
By: ali mohammed - why we use the java in ne
By: ali mohammed - why we use the java in ne
By: mizhelle - when I exported the data
By: raul - no output as well, i'm ge
By: Rajesh - thanx very much...
By: Suindu De - Suppose we are executing

You want to combine two arrays into one.

Use array_merge( ):

$garden = array_merge($fruits, $vegetables);

The array_merge( ) function works with both predefined arrays and arrays defined in place using array( ):

$p_languages = array('Perl', 'PHP');
$p_languages = array_merge($p_languages, array('Python'));
print_r($p_languages);
Array
(
    [0] => PHP
    [1] => Perl
    [2] => Python
)

Accordingly, merged arrays can be either preexisting arrays, as with $p_languages, or anonymous arrays, as with array('Python').

You can't use array_push(), because PHP won't automatically flatten out the array into series of independent variables, and you'll end up with a nested array. Thus:

array_push($p_languages, array('Python'));
print_r($p_languages);
Array
(
    [0] => PHP
    [1] => Perl
    [2] => Array
        (
            [0] => Python
        )

)

Merging arrays with only numerical keys causes the arrays to get renumbered, so values aren't lost. Merging arrays with string keys causes the second array to overwrite the value of any duplicated keys. Arrays with both types of keys exhibit both types of behavior. For example:

$lc = array('a', 'b' => 'b'); // lower-case letters as values
$uc = array('A', 'b' => 'B'); // upper-case letters as values
$ac = array_merge($lc, $uc);  // all-cases?
print_r($ac);
Array
(
    [0] => a
    [b] => B
    [1] => A
)

The uppercase A has been renumbered from index 0 to index 1, to avoid a collision, and merged onto the end. The uppercase B has overwritten the lowercase b and replaced it in the original place within the array.

The + operator can also merge arrays. The array on the right overwrites any identically named keys found on the left. It doesn't do any reordering to prevent collisions. Using the previous example:

print_r($a + $b);
print_r($b + $a);
Array
(
    [0] => a
    [b] => b
)
Array
(
    [0] => A
    [b] => B
)

Since a and A both have a key of 0, and b and B both have a key of b, you end up with a total of only two elements in the merged arrays.

In the first case, $a + $b becomes just $b, and in the other, $b + $a becomes $a.

However, if you had two distinctly keyed arrays, this wouldn't be a problem, and the new array would be the union of the two arrays.


PHP Home | All PHP Tutorials | Latest PHP Tutorials

Sponsored Links

If this tutorial doesn't answer your question, or you have a specific question, just ask an expert here. Post your question to get a direct answer.



Bookmark and Share

Comments(0)


Be the first one to add a comment

Your name (required):


Your email(required, will not be shown to the public):


Your sites URL (optional):


Your comments:



More Tutorials by David Sklar
Find Difference between two dates in PHP
Reading .CSV file in PHP
Appending One Array to Another in PHP
Removing Duplicate Elements from an Array in PHP
Sorting an Array in PHP
Iterating Through an Array in PHP
Password protecting a page in PHP
Deleting Cookies in PHP
Reading Cookie Values in PHP
Setting cookies in PHP
Encrypting and decrypting in PHP
GDBM, NDBM, DB2, DB3, DBM, and CDB Databases in PHP
Using Text-File Databases in PHP
Upload and Download files with FTP in PHP
Extract files from a .zip file using PHP

More Tutorials in PHP
PHP code to import from CSV file to MySQL
PHP code to write to a CSV file from MySQL query
PHP code to write to a CSV file for Microsoft Applications
Convert XML to CSV in PHP
Password must include both numeric and alphabetic characters - Magento
PHP file upload (Large Files)
PHP file upload prompts authentication for anonymous users
PHP file upload with IIS on windows XP/2000 etc
Error: Length parameter must be greater than 0
Multiple File Upload in PHP using IFRAME
Resume or Pause File Uploads in PHP
Exception in module wampmanager.exe at 000F15A0 in Windows 8
Handling file locks in PHP
HTML table output using Nested for loops in PHP
Count occurrences of a character in a String in PHP

More Latest News
Most Viewed Articles (in PHP )
isset() function in PHP
Parent: child process exited with status 3221225477 -- Restarting
Different versions of PHP - History and evolution of PHP
A Basic Example using PHP in AWS (Amazon Web Services)
Using Cookies in PHP
Handling BLOB in PHP and MySQL
Renaming and Removing Files in PHP
preg_replace() and preg_replace_callback() in PHP
Reading word by word from a file in PHP
Installing PHP 5.x with Apache 2.x on HP UX 11i and configuring PHP 5.x with Oracle 9i
Function to return number of digits of an integer in PHP
History and origin of PHP
.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable
Using list() in PHP
public, protected, and private Properties in PHP
Most Emailed Articles (in PHP)
.htaccess pcfg_openfile: unable to check htaccess file, ensure it is readable
Different versions of PHP - History and evolution of PHP
The new keyword and constructors in PHP
public, protected, and private Methods in PHP
preg_replace() and preg_replace_callback() in PHP
Iterating Through an Array in PHP
Appending One Array to Another in PHP
Decrypting files using GnuPG (GPG) via PHP
Setting up PHP in Windows 2003 Server IIS7, and WinXP 64
Running different websites on different versions of PHP in Windows 2003 & IIS6 platform
Warning: session_start(): open .... failed - PHP error
Malware: global $ob_starting;
Function to convert strings to strict booleans in PHP
Function to sort array by elements and count of element in PHP
Error: Length parameter must be greater than 0