boolean - php preg_match() acts weirdly -
i found this, when i'm working in regex validation on php.
i've used preg_match
function validate string.
i've printed value returned preg_match
ensure working flow.
during i've found thing. can't understand concept.
that preg_match()
returns 1 if match found. otherwise return 0. print function didn't print anything.
after gone through on php manual know of return value...
there posted follow...
preg_match() returns 1 if pattern matches given subject, 0 if not, or false if error occurred.
and used var_dump
know printed or not...
this helped me know that's boolean false.
but i'm curious know why returns boolean false, when i'm putting " ! " (not) before preg_match()
?
following code,
echo preg_match("/script/","script") // ===> returs 1 echo !preg_match("/script/","script") // ===> returns boolean false
i think have return integer 0(zero)... me know functionality? or did wrong in syntax???
and 1 thing, i've tried in opencart 2.0.0.0 admin controller module.
the !
operator return boolean value.
for unary ! operator type of result bool. value of operand converted type bool , if true of operator result false, , result true otherwise.
langspec reference: https://github.com/php/php-langspec/blob/php-5.6/spec/10-expressions.md#unary-arithmetic-operators
the normal conversion rules bool
applied value.
Comments
Post a Comment