PHP 5.3.10 vs PHP 5.5.3 syntax error unexpected '['

问题

Is it possible that this PHP code line

if ($this->greatestId()[\"num_rows\"] > 0)

works in PHP 5.5 and returns an error in 5.3??

PHP Parse error:  syntax error, unexpected \'[\' in /var/www/app/AppDAO.php on line 43

How can I change it to work under PHP 5.3?

回答1:

Array dereferencing became available in PHP 5.4 That's why this doesn't work in PHP 5.3. So you have an extra step where you need to get the array value from your function call and then you can use it:

$variable = $this->greatestId();
if ($variable["num_rows"] > 0){
      // do stuff
}

回答2:

You cant use like this if ($this->greatestId()["num_rows"] > 0) in PHP 5.3 ver use below code.

$var = $this->greatestId();
if ($var["num_rows"] > 0){
  // your code
}

回答3:

As mentioned in the PHP 5.4 notes:

As of PHP 5.4 it is possible to array dereference the result of a function or method call directly. Before it was only possible using a temporary variable.

It's not possible to do that in PHP 5.3, you need to use a variable.

来源：https://stackoverflow.com/questions/23565971/php-5-3-10-vs-php-5-5-3-syntax-error-unexpected

标签

php