If PHP text file line equals, then do something

Question

I am saving the state of a checkbox to a text file and reading it back in to show either a checked or non-checked box. The saving part is no problem - depending on whether I check or uncheck the box the value "Checked" or "Unchecked" is written to the text file. Echoing echo $lines[0]; results in either value as expected. However, when using if ($lines[0] == "Checked") as shown in my code below, the value doesn't seem to be detected and therefore the echo that follows is not executed. What is the correct syntax for this situation?

      <?php
      $file = "textfile.txt";
      $lines = file($file); 
      ?>

      <input type="hidden" name="data1" value="Unchecked" />
      <input type="checkbox" name="data1" value="Checked" class="checkbox" 
        <?php
        if ($lines[0] == "Checked") {  
        echo 'checked="checked"';  
        }  
        ?>
      />

Answer 1

You probably have a line-break in your $lines[0] variable.

What you could do is:

if (trim($lines[0]) == "Checked") {  

But what you should do, is switch to a database.

Answer 2

The value can differ based on line endings. I recommend you do the following:

if (stristr($lines[0], "unchecked")) {  
  echo '';  
}else{
  echo 'checked="checked"';  
}