quick question about checkboxes

[Anon]

Hello everyone!

I'm using checkboxes and i'm just curious if i'm right here. Isn't the value checkboxes become when they are checked "on"?

If this is true, why doesn't this work:

$totalStrand=0;

if($strand1 = "on"){
$totalStrand= $totalStrand+1;
}
if($strand2="on"){
$totalStrand= $totalStrand+2;
}

strand1 and strand2 are names of my checkboxes and currently it doesn't matter what I check, the value of totalStrands always ends up being 3. Why is this?

Thanks for your time!

[Anon]

do this instead:

if(isset($strand1)){
$totalStrand = $totalStrand + 1;
}

if the checkbox is checked, the variable is set and one will be added. if not, the variable is not set and no number will be added.

also, if you want to check if a checkbox is left empty do this:

if(!isset($strand1)){
blah...
}

[spider_man]

eg.

<input type="checkbox" name="check1" value="1">

Then the server will have a variable named 'check1' with the value '1', if it was checked, otherwise it will contain an empty string.

[Anon]

Thanks So much!!!

[Anon]

thanks!

[Anon]

Something must be wrong with my logic.
I tried that code that you gave me but now I keep getting 0 as totalStrand value.

$totalStrand=0;

if(isset($strand1)){
$totalStrand= $totalStrand+1;
}

Any ideas?

[junebug]

well, are you using the right variable names? it should be something like this:

• html -

<form action="script.php" method="post">
<input type="checkbox" name="var">
<input type="submit">
</form>

• php -

<?

if(isset($var)){
print "variable is set";
else
print "variable is not set";

?>

make sure that the name of the variable in the input is the same as the script. did that fix the problem?

[Anon]

This is what I have:

<input type="checkbox" name="strand1" value="Agriculture">Agriculture</font></td>

And then I have:
$totalStrand = '0';

if(isset($strand1)){
$totalStrand = $totalStrand + 1;
}

Is that not right??

[junebug]

okay, well, is your checkbox in a form and all that stuff? this should be what you want:

• html -

<form action="script.php" method="post">
<input type="checkbox" name="strand1">agriculture
</form>

• php -

$totalStrand = 0;
if(isset($strand)){
$totalStrand = $totalStrand + 1;
}

if you want to have the value attribute in the input tag, then you need to do a different check in your script. i would suggest just dropping out the value. if you want to keep the value="agriculture" in then change the if statement to this:

if($strand == "agriculture"){
$totalStrand = $totalStrand + 1;
}

[Anon]

when I typed in:
if(isset($strand1)){
print "variable is set";
}else{
print "variable is not set";
}

it said "variable is not set".

[Anon]

but leave out the strand number i.e. $strand1?

if(isset($strand)){
and
if($strand == 'agriculture'){

[junebug]

no no, leave the strand number in. it was just my typo. the variable name doesn't matter. its whether you are including a value in the input tag in your form.

[junebug]

• html -
  <form action="script.php" method="post">
  <input type="checkbox" name="strand1">agriculture
  </form>
• php -
  $totalStrand = 0;
  if(isset($strand1)){
  $totalStrand = $totalStrand + 1;
  }

should look like that

[Anon]

Yeah it's still not working. But thanks for your help! It's greatly appreciated.

[Anon]

I didn't read all answers but it appears that people are missing the problem.

You are using an assignment (=) instead of a comparision (==) operation in your if statements.

So if you change your code to this:

if($strand1 == "on"){
$totalStrand= $totalStrand+1;
}
if($strand2 == "on"){
$totalStrand= $totalStrand+2;
}

You will get what you originally wanted, along with some warning messages about undefined variables for any checkbox that wasn't used, but I saw someone went into that so you should be able to fix that.

[Anon]

Haha, Good catch!

this is what I would use

if ($HTTP_POST_VARS){
extract($HTTP_POST_VARS);
}

if($strand1){
$totalStrand= $totalStrand+1;
}

if($strand2){
$totalStrand= $totalStrand+2;
}

Except I would use an array as the name
strand[0], strand[1], then then just step through it with a loop.

The variable is null if it wasn't checked.

[Anon]

I agree with you, that's how I set up all of my checkboxes, but it involves a bit more explanation and code changes. Just fixing the problem was easier.

I'd have also used:
$totalStrand++;
and $totalStrans += 2;

I like to conserve code where I can and it's not detrimental to the reading of the source.