How to check if a variable is a numeric value?

Question

PHP PDO's lastInsertId() method actually returns an numeric value, but it may also return something completely different like some strange SQLSTATE code or whatever. In any case it returns not a numeric value I would like to log an error. Is there a way to safely check for that?

Answer 1

is_numeric returns true for numerical strings and false otherwise. A similar function is ctype_digit.

Answer 2

Use

is_int($value)

or

is_numeric($value)

Answer 3

is_int or is_numeric is a good way.

You can also try to cast result to (int) and check if it is > 0.