Less expensive operation
Less expensive operation

- array_keys() essentially creates a new array, using more memory. It's also
  like iterating the array twice.
- If we're going to iterate once, might as well only do it once.

ezimuel/zend-stdlib,MadCat34/zend-stdlib,akrabat/zend-stdlib,weierophinney/zend-stdlib,adamlundrigan/zend-stdlib,php-refactoring/zend-array-utility,sravanchandj/zend-stdlib