Using dynamic variables with isset()?

Question

I have a loop that has a dynamic variable in it, eg:

while(i < 10){
  echo  ${"dynamic" . $i . "var"};
  $i++;
};

I want to only echo the variable if the original var (say $dynamic3var) is set so I add:

while(i < 10){
  if(isset(${"dynamic" . $i . "var"})){
    echo  ${"dynamic" . $i . "var"};
  $i++;
  };
};

However this wont work as its still picking up $i.

Does anyone know a correct way of doing this?

what o/p you are getting on running the codes provided in answers ? — krishna
– krishna, Commented Jan 30, 2014 at 11:46
Plz post where you have declared the variable say $dynamic3var in the code — krishna
– krishna, Commented Jan 30, 2014 at 11:55

itinance · Accepted Answer · 2014-01-30 11:58:51Z

1

Since global variables are bad ideas you should rethink your code. A plain refactoring would be to use an associative array (even if it remains a global variable at the first step). Then you could work with

if( isset($dynamic[$i]) ) ...

Why are Globals evil? Read this: http://tomnomnom.com/posts/why-global-state-is-the-devil-and-how-to-avoid-using-it

answered Jan 30, 2014 at 11:58

itinance

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Comments

andy · Accepted Answer · 2014-01-30 11:39:12Z

0

Try this:

while($i < 10){
  $label = "dynamic".$i."var";

  if(isset($$label))
    echo $$label;

  $i ++;
};

answered Jan 30, 2014 at 11:39

andy

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3 Comments

MeltingDog Over a year ago

Thanks but no luck there

andy Over a year ago

Well then there is a bug elsewhere in your code or you aren't using an up to date PHP version. If I run the code on writecodeonline.com/php it works perfectly.

Sujith PS Over a year ago

Give your explanation too.

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