get value attribute of a checkbox from javascript function

Question

I am doing this :

function GETVALUE() 
{
 if(document.getElementById("requirenewpage").checked == true)
    {
        document.getElementById("requirenewpage").value;    
        var cval= parseInt(document.getElementById("requirenewpage").value);

    }
}

HTML-----------------------------

<input type="checkbox" id="requirenewpage" unchecked   value= "GETVALUE();" >

I need to insert into a mysql table , 0 or 1, which is taken from the VALUE attribute of the checkbox.....but am not able to do it...please help???

Its always inserting 0 into the database, albeit am setting the value as 1 in the function GETVALUE().....

Your HTML is invalid. Inputs (if they are checkboxes or radio buttons) have a checked attribute (which should be specified as just the unquoted value checked). If it is to be unchecked, then don't specify the attribute. — Quentin
– Quentin, Commented Jul 15, 2011 at 13:19

Nicola Peluchetti · Accepted Answer · 2011-07-15 13:42:33Z

3

Actually you don't need any of this i think. You can use this html:

  <input type="checkbox" id="requirenewpage"  value= "1" >

and the checkbox will send a value of 1 to the server if checked, otherwise it won't send anything (and the corresponding $_POST['requirenewpage'] or $_GET['requirenewpage'] won't be set).

If the checkbox is checked it's value is sent to the server and a key in the $_POST array (if you use POST) is created with the name of the checkbox and the value of hte checkbox.

you can do, serverside:

$chkboxval = 0;

if (isset($_POST['requirenewpage'])){
     $chkboxval = $_POST['requirenewpage'];
}

edited Jul 15, 2011 at 13:42

answered Jul 15, 2011 at 13:19

Nicola Peluchetti

77k32 gold badges150 silver badges197 bronze badges

Sign up to request clarification or add additional context in comments.

9 Comments

sqlchild Over a year ago

----what will this do sir, ----- isset($_POST['requirenewpage'] , does it checks that checkbox is checked or unchecked , and iS TRUE, if checkbox is checked??

sqlchild Over a year ago

how do i take the value=1 of checkbox in a variable......i did this ----- $val = $_POST('requirenewpage'); ----------will $val be 1 in this case?

Nicola Peluchetti Over a year ago

Yes isset($_POST['requirenewpage']) returns true if the checkbox is checked because if the checkbox is checked it's value is sent to the server and a key in the $_POST array (if you use POST) is created with the name of the checkbox. and yes $val will be 1 (or whatever value you set as the value of the checkbox)

sqlchild Over a year ago

so , there is no need to take a $chkboxval variable, which you have taken in your code, i will just insert $val=$_POST('requirenewpage') in my mysql table

Nicola Peluchetti Over a year ago

No you should always check if it's set because otherwise it's key is undefined and you will get a notice: i updated the answer you should do as written there.

|

Sam Dufel · Accepted Answer · 2011-07-15 15:01:47Z

1

I'm shocked that nobody has answered this correctly yet... Change the checkbox to the following:

<input type="checkbox" id="requirenewpage" name="requirenewpage" value= "1" />

The ID of an input element is used for script access and styling only, if you want to submit the element in a form it must have a name attached to it.

answered Jul 15, 2011 at 15:01

Sam Dufel

17.6k3 gold badges51 silver badges52 bronze badges

Comments

Awais Qarni · Accepted Answer · 2011-07-15 13:20:57Z

1

You are wrong with your html. Change your checkbox code from

<input type="checkbox" id="requirenewpage" "unchecked"   value= "GETVALUE();" >

to

<input type="checkbox" id="requirenewpage" onclick= "GETVALUE();" >

answered Jul 15, 2011 at 13:20

Awais Qarni

18k25 gold badges80 silver badges145 bronze badges

1 Comment

Nicola Peluchetti Over a year ago

you are right with this, but i think that's a lot more complicated than using standard html

Collectives™ on Stack Overflow

get value attribute of a checkbox from javascript function

3 Answers 3

9 Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

9 Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related