Preg match php a-zA-Z0-9 and space

Question

if (preg_match ('/[^a-zA-Z0-9]/i', $getname)) { 

I use this preg_match pattern to check if a string in php contains charachters other than a-zA-Z0-9 . I want to add space to the template ... I use ' /[^a-zA-Z0-9 ]/i' , but it doesn’t work ... how do I do this?

I want to resolve spaces, including a-zA-Z0-9

Answer 1

 if (preg_match ('/[a-zA-Z0-9 ]/', $getname)) { 

Answer 2

 preg_match('/^[a-zA-Z0-9 ]+$/', 'string')