how can we assign a javascript array from mysql database with the help of php?

I would like to know if we can select data from the database using php and assign it to a javascript array? if so what would be the syntax?

I wrote the code below but it is not working

$js_array = "[";
$result = mysql_query("SELECT item_name FROM tbl_item");
while( $row=mysql_fe开发者_如何学Gotch_array($result, MYSQL_NUM) ) {
    $js_array .= $row[0]; 
    $js_array .= ",";
}
$js_array{ strlen($js_array)-1 } = ']';

 ?>

<script>
var cities = <?php echo  $js_array; ?>
for(var i=0; i<4;i++)
alert(cities.length);

</script> 

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The simplest approach is converting to JSON with json_encode:

// with $js_array being a true array
var cities = <?php echo json_encode($js_array)?>;

Note, that there are esoteric cases, where this solution might not work. On the other hand, the advantage is, that json_encode takes over all quoting needs.

---

Use json_encode

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You should not echo the array object.

Iterate the array and echo the value.

<?php foreach( $js_array as $value) echo "'$value',"; ?>