正则表达式不包括单词

Question

I want to create a regular expression for a string, if that string exit then it should return false.

i am using it on select option, so if value is Please select then it will be false

My impression:

^/(?!Please select)([a-z0-9]+)$ 

Got working expression as: /^(?!.*Please select)([a-zA-Z0-9]+)$/

Answer 1

This regex should do:

^(?!.*Please select).+$

It will select all line that does not contain Please select anywhere in the line.
This will work with any character on the line, nut just letter and numbers.

Answer 2

If you are using javascript. It will be easier and more readable to find the match and just to reverse the match result. Something like:

 let unmatched = yourLine.match(/Please select/g) == null ? true: false;

Answer 3

This is a simple way to validate your input against presence of "Please select":

 function isValid(input) { let regex = /Please select/; return !regex.test(input); } console.log(isValid("Please select following")); //false console.log(isValid("selected answer!")); //true