将服务器端变量传递给PHP中的Javascript [重复]

Question

This question already has an answer here:

• Efficient way to Pass variables from PHP to JavaScript [duplicate] 8 answers

What is the best way to pass a server-side PHP variable to Javascript?

To simplify the problem assume that we have a variable in PHP ($phpVar) and we want to assign its value to a Javascript variable (jsVar)

Javascript files are loaded in html - they are not created dynamic!

Some food for thought:

1. Print with PHP before loading Javascript files:

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

2. Store in DOM (in hidden elements)

a. in PHP:

    <span data-name="phpVar" data-value="<?php echo $phpVar?>"></span>

b. Read in Javascript files (assuming jQuery available):

    var jsVar= $('span[data-name="phpVar"]').attr('data-value');

3. Ask it with AJAX after page has loaded

Obviosly not the best solution. Doesn't fit to all scenarios and requires an additional request...

In conclusion:

• They both seem ugly to me... Is there a better approach?
• Is there any frameworks that can handle this dependecies? Please keep server reconfiguration minimal.

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Answer 1

It depends on the situation, but in common, predominantly to use first case. But don't forget about quotes if you pass a string:

<script language="javascript" type="text/javascript">
    var jsVar = '<?php echo $phpVar?>';
</script>