Is using curly braces in variables good practice in php [closed]

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Some developers uses curly braces in their PHP code and some simply concatenates them.

For example, these 2 lines of code are totally valid in PHP

echo "<h1>{$row['title']}</h1>";

echo "<h1>" . $row['title'] . "</h1>";

The output of the code is the same at the end end but which one is consider a good coding practice?

Thank you, J

---

Using curly brace syntax is slightly slower. Consider the following test:

<?php

  $array = array('key'=>'val');

  $start1 = microtime(TRUE);
  for ($i = 0; $i < 100000; $i++) {
    $str = "<tag>{$array['key']}</tag>";
  }
  $end1 = microtime(TRUE);
  $result1 = $end1 - $start1;

  $start2 = microtime(TRUE);
  for ($j = 0; $j < 100000; $j++) {
    $str = "<tag>".$array['key']."</tag>";
  }
  $end2 = microtime(TRUE);
  $result2 = $end2 - $start2;

  $start3 = microtime(TRUE);
  for ($k = 0; $k < 100000; $k++) {
    $str = '<tag>'.$array['key'].'</tag>';
  }
  $end3 = microtime(TRUE);
  $result3 = $end3 - $start3;

  echo "1: $result1\n2: $result2\n3: $result3\n";

?>

On my PHP/5.2.19-win32 system, the first test (with curly braces) is slightly slower (~7%). However, the difference is so small as to be not worth worrying about, and I would say do whatever you are most comfortable with.

Slightly counter-intuitively, the second test is consistently faster than the third (~2%) - double quotes are faster than single quotes - and I would have expected it to be the other way around.

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It's useless to ask for best practice, as you have not written which style you prefer. If it helps you to read your strings with curly brackets, use them, they work. There are multiple ways to solve the problem, just to name a few:

echo "<h1>{$row['title']}</h1>";

echo "<h1>" . $row['title'] . "</h1>";

echo "<h1>", $row['title'], "</h1>";

printf("<h1>%s</h1>", $row['title']);

echo sprintf("<h1>%s</h1>", $row['title']);

?><h1><?php echo $row['title']; ?></h1><?php # thx, Jaime :)

...

Choose what is readable for you. Best practices you learn while doing. The language is a tool to suit your needs.

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Actually, using single quotes for strings is more efficient in PHP.

So, I would say no, using curly braces around variables in string is not a good practice.

Using the following syntax is both more efficient and more readable (imho) :

echo '<h1>' . $row['title'] . '</h1>';

---

I've always found the echo '<h1>' . $row['title'] . '</h1>'; easier to read.

---

I've never used curly brackets around variables myself, ever. Just seems very long winded to me!

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If you do not have an agreed upon standard already, I recommend you use an existing one such as Zend or Pear. For example, with respect to your question, the Zend guide specifically states:

Variable substitution is permitted using either of these forms:

$greeting = "Hello $name, welcome back!";

$greeting = "Hello {$name}, welcome back!";

---

I don't see anything wrong in that, unless you don't properly escape user-submitted HTML, which you can forget to do in either case.

Some may say that single quotes are more efficient, but all tests I see were made years ago on that old hardware, which doesn't speaks for their credibility. Tests on current hardware show that single quotes on a 100000 run is only 7 milliseconds faster than curly braces, which can't be an argument.

Use what you think is more readable because developer's time these days is much more expensive than a computer time. Let you servers do their jobs.