PHP的简写为isset（）？ [重复]

Question

This question already has an answer here:

• What is the PHP shorthand for: print var if var exist 11 answers

Is there a shorthand way to assign a variable to something if it doesn't exist in PHP?

if(!isset($var) {
  $var = "";
}

I'd like to do something like

$var = $var | "";

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Answer 1

Update for PHP 7 (thanks shock_gone_wild)

PHP 7 introduces the so called null coalescing operator which simplifies the below statements to:

$var = $var ?? "default";

Before PHP 7

No, there is no special operator or special syntax for this. However, you could use the ternary operator:

$var = isset($var) ? $var : "default";

Or like this:

isset($var) ?: $var = 'default';