PHP Program to Convert Array to Query String

This article will show you how to convert an array to a query string in PHP. The Query String is the part of the URL that starts after the question mark(?).

Example:

Input: $arr = (
    'company' => 'GeeksforGeeks',
    'Address' => 'Noida',
    'Phone' => '9876543210'
);
Output: company=GeeksforGeeks&Address=Noida&Phone=9876543210

There are two methods to convert an array to query strings, these are:

• Using http_build_query() Method
• Using urlencode() and rtrim() Methods

Using http_build_query() Method

The http_build_query() function is used to generate a URL-encoded query string from the associative (or indexed) array.

Syntax:

string http_build_query( 
    $query_data, 
    $numeric_prefix, 
    $arg_separator, 
    $enc_type = PHP_QUERY_RFC1738 
)

Example: This example uses http_build_query() Method to convert associative array into query sting.

PHP

<?php

$arr = array(
    'company' => 'GeeksforGeeks',
    'Address' => 'Noida',
    'Phone' => '9876543210'
);

$queryStr = http_build_query($arr);

echo $queryStr;

?>

Output

company=GeeksforGeeks&Address=Noida&Phone=9876543210

Using urlencode() and rtrim() Methods

First, we will create an empty string and then use foreach loop to merge key and encoded values with equals and & symbol and at least trim the & symbol from right side.

• The urlencode() function is used to encode the URL. This function returns a string which consist all non-alphanumeric characters except -_. and replace by the percent (%) sign followed by two hex digits and spaces encoded as plus (+) signs.
• The rtrim() function is used to remove the white spaces or other characters (if specified) from the right side of a string.

Syntax:

string urlencode( $input )
rtrim( $string, $charlist )

Example: This example uses urlencode() and rtrim() methods to convert associative array into query sting.

PHP

<?php

// Crreate an Array
$arr = array(
    'company' => 'GeeksforGeeks',
    'Address' => 'Noida',
    'Phone' => '9876543210'
);

// Create an empty string
$queryStr = '';

// Loop to iterate array elements
foreach ($arr as $key => $value) {
    $queryStr .= $key . '=' . urlencode($value) . '&';
}

// Remove the & symbol of right side
$queryStr = rtrim($queryStr, '&');

// Print the Query String
echo $queryStr;

?>

Output

company=GeeksforGeeks&Address=Noida&Phone=9876543210