PHP is_null

(PHP 4 >= 4.0.4, PHP 5, PHP 7)

is_null — Detect whether the variable is NULL

Description?

boolis_null ( mixed$var )

if var is null then return TRUE, otherwise returns FALSE.

View The NULL type knows when a variable is considered NULL and when it is not.

See NULL, is_bool(), is_numeric(), is_float(), is_int(), is_string(), is_object(), is_array(), is_integer () and is_real().

The above has introduced PHP is_null, including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.