---
title: "Ruby 2.4 Regexp#match? not polluting global variables"
description:
  "Ruby 2.4 now allows matching a regex without updating global variables using
  Regexp#match?. This is a faster option to match regexes when we don't care
  about the match data"
canonical_url: "https://www.bigbinary.com/blog/ruby-2-4-implements-regexp-match-without-polluting-global-variables"
markdown_url: "https://www.bigbinary.com/blog/ruby-2-4-implements-regexp-match-without-polluting-global-variables.md"
---

# Ruby 2.4 Regexp#match? not polluting global variables

Ruby 2.4 now allows matching a regex without updating global variables using
Regexp#match?. This is a faster option to match regexes when we don't care about
the match data

- Author: Rohit Kumar
- Published: November 4, 2016
- Categories: Ruby 2.4, Ruby

Ruby has many ways to match with a regular expression.

#### Regexp#===

It returns true/false and sets the \$~ global variable.

```ruby

/stat/ === "case statements"
#=> true
$~
#=> #<MatchData "stat">

```

### Regexp#=~

It returns integer position it matched or nil if no match. It also sets the \$~
global variable.

```ruby

/stat/ =~ "case statements"
#=> 5
$~
#=> #<MatchData "stat">

```

### Regexp#match

It returns match data and also sets the \$~ global variable.

```ruby

/stat/.match("case statements")
#=> #<MatchData "stat">
$~
#=> #<MatchData "stat">

```

### Ruby 2.4 adds Regexp#match?

[This new method](https://bugs.ruby-lang.org/issues/8110) just returns
true/false and does not set any global variables.

```ruby

/case/.match?("case statements")
#=> true
```

So `Regexp#match?` is good option when we are only concerned with the fact that
regex matches or not.

`Regexp#match?` is also faster than its counterparts as it reduces object
allocation by not creating a back reference and changing `$~`.

```ruby

require 'benchmark/ips'

Benchmark.ips do |bench|

  EMAIL_ADDR = 'disposable.style.email.with+symbol@example.com'
  EMAIL_REGEXP_DEVISE = /\A[^@\s]+@([^@\s]+\.)+[^@\W]+\z/

  bench.report('Regexp#===') do
    EMAIL_REGEXP_DEVISE === EMAIL_ADDR
  end

  bench.report('Regexp#=~') do
    EMAIL_REGEXP_DEVISE =~ EMAIL_ADDR
  end

  bench.report('Regexp#match') do
    EMAIL_REGEXP_DEVISE.match(EMAIL_ADDR)
  end

  bench.report('Regexp#match?') do
    EMAIL_REGEXP_DEVISE.match?(EMAIL_ADDR)
  end

  bench.compare!
end

#=> Warming up --------------------------------------
#=>          Regexp#===   103.876k i/100ms
#=>           Regexp#=~   105.843k i/100ms
#=>        Regexp#match    58.980k i/100ms
#=>       Regexp#match?   107.287k i/100ms
#=> Calculating -------------------------------------
#=>          Regexp#===      1.335M (± 9.5%) i/s -      6.648M in   5.038568s
#=>           Regexp#=~      1.369M (± 6.7%) i/s -      6.880M in   5.049481s
#=>        Regexp#match    709.152k (± 5.4%) i/s -      3.539M in   5.005514s
#=>       Regexp#match?      1.543M (± 4.6%) i/s -      7.725M in   5.018696s
#=>
#=> Comparison:
#=>       Regexp#match?:  1542589.9 i/s
#=>           Regexp#=~:  1369421.3 i/s - 1.13x  slower
#=>          Regexp#===:  1335450.3 i/s - 1.16x  slower
#=>        Regexp#match:   709151.7 i/s - 2.18x  slower

```

## Links

- [Human page](https://www.bigbinary.com/blog/ruby-2-4-implements-regexp-match-without-polluting-global-variables)