Dynamically Changing the Name of a Variable

[Vigile]

Lets say I have a POST sending along an unknown number of check box variables, and in the next PHP doc in the submit URL, I want to do somethign with each of those values. I have conveniently used a loop in PHP to create the names of hte check boxes: Check1 - Check8 (but it could later be changed from Check1-CHeck11, but I don't want to have to alter this code).

In the submit.php code, I want to be able to cycle through all of these check boxes. I have a way to loop through the total number of check boxs that were there, but I don't know how to dynamicly create each variable name to test: ie I want to do:

Is Check1 = 1?
Is Check2 = 1?
Is Check3 = 1?

But I cant figure out how to change the 1/2/3 part of the variable name as I go.

Is there anything like:

for ($i=0; $i<checktotal; $i++) {
if ($Check$i ==1)
do something
}

Thanks!

[Cyborg from DH]

or send all the checkboxes along with an array.

[Zoombie]

for ($i=0; $i<maxnumberofchecks; $i++) {
  $var="Check$i";
  if(isset($$var)){
    if ($$var==1)
      // do something
    }
  }else{
    break;
  }
} 

It looks like you're working with register_globals set to on, though...the recommendation would be to learn how to work without register_globals, as it makes it extremely easy to leave loopholes in your code.

[Vigile]

Thanks!

[Gamefreak]

Zoombie, I don't think you can use $$var to represent the variable.

for ([color=#0000cc]$i
 
Wouldn't you have to use:
 
[color=#006600]=[/color][color=#0000cc]0[/color][color=#006600]; [/color][color=#0000cc]$i[/color][color=#006600]<[/color][color=#0000cc]maxnumberofchecks[/color][color=#006600]; [/color][color=#0000cc]$i[/color][color=#006600]++) { 
  [/color][color=#0000cc]$var[/color][color=#006600]=[/color][color=#cc0000]"\$Check$i"[/color][color=#006600]; 
  if(isset(eval($var)[/color][color=#006600])){ [/color]
[color=#006600]	if (eval($var)[/color][color=#006600]==[/color][color=#0000cc]1[/color][color=#006600]) 
	  [/color][color=#ff9900]// do something 
	[/color][color=#006600]} 
  }else{ 
	break; 
  } 
} [/color]

[/color]

[MUG]

Zoombie, I don't think you can use $$var to represent the variable.

for ([color=#0000cc]$i
 
Wouldn't you have to use:
 
[color=#006600]=[/color][color=#0000cc]0[/color][color=#006600]; [/color][color=#0000cc]$i[/color][color=#006600]<[/color][color=#0000cc]maxnumberofchecks[/color][color=#006600]; [/color][color=#0000cc]$i[/color][color=#006600]++) { 
  [/color][color=#0000cc]$var[/color][color=#006600]=[/color][color=#cc0000]"\$Check$i"[/color][color=#006600]; 
  if(isset(eval($var)[/color][color=#006600])){ [/color]
[color=#006600]	if (eval($var)[/color][color=#006600]==[/color][color=#0000cc]1[/color][color=#006600]) 
	  [/color][color=#ff9900]// do something 
	[/color][color=#006600]} 
  }else{ 
	break; 
  } 
} [/color]

[/color]

You can use $$var. That is called a 'variable variable'.

However your example will not work.

[Cyborg from DH]

you can also have string named variables:

${"hello this is a variable"}

[Gamefreak]

Cool! I never knew that before. Whaddya know? I learned something new while I was trying to help somethone out!

[TeKnIcIaN]

I do something like this for changing the display order of items in my catalog scripts. My post vars are something like "displayorder_1" to "displayorder_50" or whatever.

foreach ($HTTP_POST_VARS as $key => $value) {
    list($crap, $id) = explode("displayorder_", $key);
    if ($id > 0) {
        // do stuff
    }
} 

Works great for me!

[MUG]

I do something like this for changing the display order of items in my catalog scripts. My post vars are something like "displayorder_1" to "displayorder_50" or whatever.

foreach ($HTTP_POST_VARS as $key => $value) {
    list($crap, $id) = explode("displayorder_", $key);
    if ($id > 0) {
        // do stuff
    }
} 

Works great for me!

BTW, here is a trick about list():

foreach ($HTTP_POST_VARS as $key => $value) {
    list(,$id) = explode("displayorder_", $key); // you don't have to fill the first argument if you don't want to use that key
    if ($id > 0) {
        // do stuff
    }
}