How to Use Pattern Matching Operator in Ruby

Checking any data against other data is known as pattern matching. The article discusses Ruby’s basic pattern matching operator (=~) briefly.

Pattern Matching Operator (=~) in Ruby

The pattern matching operator (=~) matches a regular expression against a string. The operator (=~) returns the offset if the string meets the expression and returns nil otherwise.

Regexp and String define this operator the same way, so the order of the two does not matter.

Example Code:

p 'David is a boy' =~ /boy/
p(/boy/ =~ 'David is a boy')
p 'David is a boy' =~ /boy/
p(/boy/ =~ 'David is a boy')

Output:

11
11
11
11

If there’s no match, nil is returned instead.

Example Code:

p 'David is a boy' =~ /girl/
p(/girl/ =~ 'David is a boy')

Output:

nil
nil