Changing value of a javascript variable globally

Question

I have a page 1.php and the code goes here(just a clone)

<?php
include '2.php'
?>
<script>
function rename(){
var x='renamedvalue';
}
</script>
<input type="button" onclick="return rename();">

And the page 2.php

<script>
var x ='somevalue';
</script>

I have to change the value of this variable onclick button event on page1.

@AliBz. Can you illustrate by posting an answer please. – lakshya_arora Jun 06 '13 at 08:01 — lakshya_arora, Jun 06 '13 at 08:01

score 3 · Answer 1 · answered Jun 06 '13 at 08:02

3

Since you're including 2.php into 1.php, you'll end up having a single page. You could create a global Javascript value, like you already did in 2.php, like this:

<script>
var x ='somevalue';
</script>

Your problem in 1.php lies here:

var x='renamedvalue';

With this snippet, you are redefining a variable named x inside your rename function. To use the global variable x, change the line above to exclude the "var" (which redeclares another local value "x" inside rename()):

x='renamedvalue';

answered Jun 06 '13 at 08:02

Filippos Karapetis

4,367
21
39

what if i have to change value of a php variable. – lakshya_arora Jun 06 '13 at 08:15
I'm sorry, I don't understand your question. How would you like to change a PHP value? Under which circumstances? Which value is that? – Filippos Karapetis Jun 06 '13 at 08:18
I mean just like a javscript variable is it possible to change the value of a global php variable. – lakshya_arora Jun 06 '13 at 08:19
Yes, it is possible to change a value of a global PHP variable, just by doing $foo = "newvalue". If you are inside a function, you'll need to declare that it is a global variable, with "global $foo;" at the top of the function – Filippos Karapetis Jun 06 '13 at 08:20
i mean on clicking a button. – lakshya_arora Jun 06 '13 at 08:21
You will need to submit the new value either by AJAX or by an HTML form. Check here, for example: http://stackoverflow.com/questions/1960240/jquery-ajax-submit-form – Filippos Karapetis Jun 06 '13 at 08:25

score 1 · Answer 2 · answered Jun 06 '13 at 08:03

1

If you want to pass variables between JS and PHP its probably easier to use forms:

<script>
function rename(){
    var x='renamedvalue';
    document.getElementById("x").value = x;
}
</script>
<form action="2.php" method="post">
<input type="hidden" value="" id="x" name="x">
<input type="button" onclick="return rename();">
</form>

page2.php

<script>
var x ='<?php print $_POST["x"] ?>';
</script>

You will need to perform some input cleaning but you get the idea

answered Jun 06 '13 at 08:03

Bloafer

1,324
7
12

If you wanted to keep the variables on the same page you could use an Ajax method of passing the vars, but it would work in a similar way – Bloafer Jun 06 '13 at 08:10

score 0 · Answer 3 · answered Jun 06 '13 at 08:03

defining variable outside the js function make it global and allow to change thee value on onclick event.

<?php
include '2.php'
?>
<script>
var x = ''; //global variable
function rename(){
x='renamedvalue';
}
</script>
<input type="button" onclick="return rename();">

score 0 · Answer 4 · answered Jun 06 '13 at 08:03

0

you must use the global variable x

write x='renamedvalue' instead of var x='renamedvalue'

answered Jun 06 '13 at 08:03

Mohammad Masoudian

3,483
7
27
45

Changing value of a javascript variable globally

4 Answers4