PHP: array to string?

hi,
Lets say I want to get the contents of a simple array:

$arr = array(“p”, “q”, “r”, “s”);

Into a string, with each element seperated by a "+", preferably with no trailing "+".is there any function that converts the values of an array to string?Better yet, is there a function for sorting strings?

This simple function converts a PHP array to a string containing a PHP array declaration. It can be used to put an array into a database field. It can then be retrieved and eval()'d in another script.

Code:

---

<?php

$arr = array('h','e','l','l','o');
$string = implode($arr, '');

?>

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The function below facilitates the process of converting an array to a string. Very useful for building SQL insert queries with arrays of data.

Code:

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<?php 
function array2str($array, $pre = '', $pad = '', $sep = ', ') 
{ 
    $str = ''; 
    if(is_array($array)) { 
        if(count($array)) { 
            foreach($array as $v) { 
                $str .= $pre.$v.$pad.$sep; 
            } 
            $str = substr($str, 0, -strlen($sep)); 
        } 
    } else { 
        $str .= $pre.$array.$pad; 
    } 
 
    return $str; 
} 
?>

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I’ve been working a great deal with vBulletin, our forums system, and in doing so have had to brush on my PHP. Through the course of preparing the system for the summer I’ve come across a few PHP functions that I was not aware. Here’s a few that you may not know about:

implode: takes an array of strings and concatenates them, using $glue as a separator.

Example: string implode (string $glue, array $pieces)
$before = array(’one’, ‘two’, ‘three’);
$after = implode(”,”, $before);
echo $after;

Produces:one,two,three

Arrays are not automatically passed by reference in PHP (unlike C, for instance). As with other variables, however, you can write your functions to accept arrays as pass-by-reference arguments. Of course, this applies only to PHP 4.

Code:

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Create an array of user information with defaults, then fill it with information. */
$user_info = array('lastname' => '',
                  'initial' => '',
                  'firstname' => '',
                  'homedir' => '');
$user_info['lastname'] = 'User';
$user_info['initial'] = 'L.';
$user_info['firstname'] = 'Joe';
$user_info['homedir'] = '/home/joeluser';

/* Filling an indexed array with the letters of the English alphabet. */
$arr = array();
for ($i = 97; $i < 123; $i++) {
    $arr[] = chr($i);
}
print_r($arr);

/* Do the same thing, but make an array containing two arrays, one of uppercase
 * letters and one of lowercase. */
$arr = array();
for ($i = 97; $i < 123; $i++) {
    $arr['lowercase'][] = chr($i);
    $arr['uppercase'][] = chr($i - 32);
}
print_r($arr);

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