[FIXED] What is the meaning of three dots (...) in PHP?

Issue

While I am installing Magento 2 on my Server, I got an error. After investigating the code and found that there is are three dots (...), which is producing the error. I included the code I found below:

return new $type(...array_values($args));

What is this operator called, and what is its purpose?

Solution

This is literally called the ... operator in PHP, but is known as the splat operator from other languages. From a 2014 LornaJane blog post on the feature:

This feature allows you to capture a variable number of arguments to a function, combined with "normal" arguments passed in if you like. It's easiest to see with an example:

function concatenate($transform, ...$strings) {
  $string = '';
  foreach($strings as $piece) {
      $string .= $piece;
  }
  return($transform($string));    }

echo concatenate("strtoupper", "I'd ", "like ", 4 + 2, " apples");

(This would print I'D LIKE 6 APPLES)

The parameters list in the function declaration has the ... operator in it, and it basically means " ... and everything else should go into $strings". You can pass 2 or more arguments into this function and the second and subsequent ones will be added to the $strings array, ready to be used.

Answered By - Saumya Rastogi

Answer Checked By - Marie Seifert (PHPFixing Admin)