I just want to know how can I display a javascript variable into html?
Below is my php code:
var duration = <? echo $postduration; ?>;
(The variable above uses php to retrieve a php variable)
Thank you
6 Answers
Make your code more concise with jQuery:
(1) Add this in your <head>:
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
(2) Create an element where you want the variable to be displayed, and give it an ID, e.g.:
<span id="printHere"></span>
(3) Add this in your JavaScript:
var duration="<?php echo $postduration ?>";
$('#printHere').html(duration);
For your PHP, try the following two options:
<?=$postduration?>
or...
<?php echo $postduration; ?>
13 Comments
BruceyBandit
Hi, I am actually jquery code already but it does not display the text. I have the relevant script tag but it is not displaying anything in my span. I will display my code in a Jsfiddle so you can see it. jsfiddle.net/SLbKX/4, Do I need to display the php variable in php tags above the jquery or can it go below the jquery because at the moment the php variable is below the jquery code
calebds
It should go above so that you are referencing a variable that exists already.. Assuming you have it laid out the way it looks in your jsfiddle, it should work if PHP is generating the page. You are editing a .php file, right?
BruceyBandit
Yes it is a php file, it is still not displaying it suprisingly, my code is in this updated fiddle, jsfiddle.net/SLbKX/7, I can't see anything wrong but I don't know why it is not working
calebds
@user1131869 when you hit CTRL+U in the browser you should see the value written there in the JavaScript. See my update on PHP syntax.
BruceyBandit
Still not displaying it in the span, all spellings are correct, cannot see a mistake, tried both your php syntax's but still doesn't display anything
|
Why don't use just display the php variable directly into the html?
Lets just say $postduration echos "some." Here is the javascript code to echo "some":
Here is <script>document.write(duration)</script> text.
Here will be the output:
Here is some text.
2 Comments
BruceyBandit
Because I want to use javascript for calculation on that variable and php requires page loads when calculation changes while javascript doesn't
Rogel Garcia
@user1131869 Will you do the calculation with PHP or with Javascript?
Here's a way to add a DIV to a page with the content of the DIV being the value of your PHP var:
<script>
var duration = <? echo $postduration; ?>;
var div = document.createElement("DIV");
div.appendChild(document.createTextNode(duration));
document.body.appendChild(div);
</script>
Comments
No, wait, that's wrong. First of all, the javascript above does not "retrieve" anything from anywhere (neither php, nor anyplace else). Php generates the javascript, meaning that if $postduration is 5, you will get var duration = 5;, and if postduration = "test", you will get var duration = test; (which is invalid javascript and will crash/cause unwanted things to happen in your application.
Last, to get a variable from javascript into html, you either replace the content of some other object (with innerHTML or something like that), or you create a new element and insert that into the page.
Example here: http://jsfiddle.net/SLbKX/
1 Comment
BruceyBandit
I just want to know that can a <span> tag have 2 id's, because I want to display the content from the variable in a span but I am thinking if I can use 1 id to display the content from the variable and another id to do some calculation on that span?
The code should be like that, use the "{$}" to put a variable in, and the "" are important.
$_var=2;
echo "hi var is {$_var}";
uses javascript to retrieve a php variable. Do you want that the javascript read a value that is stored on the server? If this is the case what you need is AJAX.