Returning JSON from PHP to JavaScript?

Question

I have a PHP script that's being called through jQuery AJAX. I want the PHP script to return the data in JSON format to the javascript. Here's the pseudo code in the PHP script:

$json = "{";
foreach($result as $addr)
{
    foreach($addr as $line)
    {
     $json .= $line . "\n";
    }
    $json .= "\n\n";
}
$json .= "}";

Basically, I need the results of the two for loops to be inserted in $json.

Answer 1

Php has an inbuilt JSON Serialising function.

json_encode

json_encode

Please use that if you can and don't suffer Not Invented Here syndrome.

Answer 2

There's a JSON section in the PHP's documentation. You'll need PHP 5.2.0 though.

As of PHP 5.2.0, the JSON extension is bundled and compiled into PHP by default.

If you don't, here's the PECL library you can install.

<?php
    $arr = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);

    echo json_encode($arr); // {"a":1,"b":2,"c":3,"d":4,"e":5}
?>

Answer 3

Usually you would be interested in also having some structure to your data in the receiving end:

json_encode($result)

This will preserve the array keys as well.

Do remember that json_encode only works on utf8 -encoded data.