Question

What will be the output if we replace the line $num = preg_grep(“/[0-5]/”, $number); with $num = preg_grep(“/[0-5]/”, $number, PREG_GREP_INVERT);?

(a) Array([0]=>0 [1]=>1 [2]=>two [3]=>three [4]=>four [5]=>5)

(b) Array([2]=>two [3]=>three [4]=>four)

(c) Array([1]=> 1)

(d) Array([0]=>0 [5]=>5)

I have been asked this question by my school teacher while I was bunking the class.

This question is from Introduction to Preg in PHP in section Objects and Databases in PHP of PHP

Answer 1

Right choice is (b) Array([2]=>two [3]=>three [4]=>four)

To elaborate: When we include PREG_GREP_INVERT, this will invert our data, so instead of outputting numbers it will output our non-numeric values.