incorrect echo still works

[Peter Knight]

I noticed an echo statement was coded incorrectly and yet it still worked 

Any ideas why the project_managers field outputs properly ...

<?php
  if ($page->projects_managers){
  echo "<strong>Project Managers:</strong> $page->projects_managers </br>";
}
 else{
   echo ""; 
 }
?>

 ...when it should probably be as follows (concatenated)

<?php
  if ($page->projects_managers){
  echo "<strong>Project Managers:</strong>" . $page->projects_managers . "</br>";
}
 else{
   echo ""; 
 }
?>

[kongondo]

A variable in double quotes will get parsed fine. If your first code it was in single quotes you would see $page->projects_managers instead . So, the code is not incorrect. I do like to concatenate though for code readability/highlighting..

http://www.scriptingok.com/tutorial/Single-quotes-vs-double-quotes-in-PHP

Edited January 15, 2015 by kongondo

[Jan Romero]

This is a feature of PHP. String literals with double quotes (") will evaluate the variables within. For clarity, you could also enclose the variable in curly brackets ({}) like so:

echo "You must be the pride of {$subject_hometown}!";

Only if you use single quotes (') the string will be parsed as-is, and you must use concatenation or other string operations to change it. Note that this means that within single quotes, escape sequences will not work either, so you can’t do the following, even though there are no variables in there:

echo '\r';

----

Added by Nico:

More infos: http://stackoverflow.com/questions/10512452/php-using-a-variable-inside-a-double-quotes (and I marked it as solved)

Edited January 15, 2015 by Nico Knoll

[adrian]

You can do this though:

echo '<strong>"Project Managers":</strong>' . my_function($page->projects_managers) . "\r";

In words - you can mix single and double quotes in the same statement. In my theoretical example above I wanted "Project Managers" to be echoed in double quotes, then run a function on $page->project_managers, hence the concatenation, and then use an escaped "\r", which is why I switched from single quotes to double quotes in the same echo statement.

EDIT: Of course you could always use double quotes and escape as needed like below, but I like the above version better:

echo "<strong>\"Project Managers\":</strong>" . my_function($page->projects_managers) . "\r";