pass associative array from php to javascript [duplicate] - php

Question

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Closed 11 years ago.
Possible Duplicate:
How to pass an array of strings from PHP to Javascript using $.ajax()?
I want to pass a associative array from php code to javascript code. Please help me. how do I do this ? Is JSON helpful in this matter? If yes then please provide a simple code for help. Thank you.
From comment below:
HTML + PHP code
<td>
<input type="text" style="width:70;" name="<?php echo $quantity;?>" id="<?php echo $quantity;?>" onkeyup="check_valid_range('<?php echo $itemName;?>','<?php echo $quantity;?>',<?php echo json_encode($product_inventory);?>);">
</td>
<script type="text/javascript">
function check_valid_range(product_field, quantity_field, inventory){
var product = document.getElementById(product_field).value;
var quantity = document.getElementById(quantity_field).value;
var v = inventory[product];
alert(v);
}
</script>

Answer 1

JSON is perfect:
<?php
$mySweetJSONString = json_encode($myAssocPHPArray);
?>
<script>
var iWantThePHPArrayHere = <?php echo $mySweetJSONString; ?>;
</script>
User pst brought up these concerns:
"array("</script>") -- darn, just broke this "perfect" approach."
It seems to work because (</script> => <\/script>): jsFiddle
"What about ]]> which could occur in XHTML?"The string is able to be transferred.jsFiddle
Update:
In regards to debugging the problem with the JS:
Are there any errors in the console? One of your document.getElementById(...) might be returning a null. Therefore the member value doesn't exist.

Answer 2

I always believed JSON were invented for this:
<script>
var myArray = <?=json_encode($myArray)?>;
</script>
This will render like this:
<script>
var myArray = {"key":"value","key2":"value2",...};
</script>
Safeness
This is perfectly safe for javascript, as JSON is a subset of the javascript syntax. This means that any JSON string can be treated as Javascript.
PHP's json_encode() is perfectly safe when embedding JSON in <script> tags too, because PHP escapes the / character:
json_encode('</script>');
=> "<\/script>"
So it's not possible to write </script>, which is the only way to escape a <script> tag. (Everything in a <script> tag is part of the script, it's not parsed as HTML.) JSON allows to escape the / for this purpose.
So no JSON string can escape a <script> tag.