Ruby: What does the "!~" operator mean? [duplicate]

Question

When declaring syntax such as:

a !~ b

where a,b are variables, what does it mean?

Answer 1

It is negation of =~, a regex match.

"a" !~ /b/
# => true

It is useful when you want to check whether a string does not match a certain pattern. For example, if you want to check if string s includes only numbers, then you can do:

s !~ /\D/