send data from php to javascript [duplicate]

Answer 1

Simple AJAX approach.

Put all your data into single array. Then use json_encode to encode your data to JSON format.

$data_array = array();

//assigning your data to single array here
$data_array['param1'] = 'value1';

echo json_encode($data_array);

Then in your JavaScript code use AJAX to call you script. For example use great jQuery library for this (http://api.jquery.com/jQuery.getJSON/).

<script type="text/javascript">    

$.getJSON('http://www.example.com/my_script.php', function(data) {
    alert(data.param1); //this should alert 'value1'
});

Answer 2

To communicate data structures from PHP to Javascript, inject a JSON value like this:

<?php
     $xdata = array(
          'foo'    => 'bar',
          'baz' => array('green','blue')
     );
?>
<script type="text/javascript">
    var xdata = <?php echo json_encode($xdata); ?>;

    alert(xdata['foo']);
    alert(xdata['baz'][0]);

    // Dot notation can be used if key/name is simple:
    alert(xdata.foo);
    alert(xdata.baz[0]);
</script>

This can be used to properly escape scalars, arrays, objects, etc.

Answer 3

There's the AJAX method, and there's the echoing method. The former is more flexible, while the latter is a lot simpler and doesn't require you to cope with AJAX errors.

For the former, there are plenty of examples around the place on how to use AJAX. The latter can be achieved quite simply:

<script type="text/javascript">
var phpVar = <?php echo ($phpVar); ?>;
</script>

Which approach is approporite depends on what data your javascript needs and what it needs it for. If you're needing to do a lot of server interaction, then working with AJAX is the avenue you should be investigating. However, if all you need is an initial value to initialize a javascript, then the latter approach is a lot easier to implement.