CODEWITHSUNDEEP
rubystring
John
John

Reputation: 4706

String containment

Is there a way to check in Ruby whether the string "1:/2" is contained within a larger string str, beside iterating over all positions of str?

Upvotes: 2

Views: 410

Answers (3)

toniedzwiedz
toniedzwiedz

Reputation: 18563

You can use the include? method

str = "wdadwada1:/2wwedaw"
# => "wdadwada1:/2wwedaw"
str.include? "1:/2"
# => true

Upvotes: 6

the Tin Man
the Tin Man

Reputation: 160551

The simplest and most straight-forward is to simply ask the string if it contains the sub-string:

"...the string 1:/2 is contained..."['1:/2']   
# => "1:/2"
!!"...the string 1:/2 is contained..."['1:/2'] 
# => true

The documentation has the full scoop; Look at the last two examples.

Upvotes: 4

Wayne Conrad
Wayne Conrad

Reputation: 108049

A regular expression will do that.

s =~ /1:\/2/

This will return either nil if s does not contain the string, or the integer position if it does. Since nil is falsy and an integer is truthy, you can use this expression in an if statement:

if s =~ /1:\/2/
  ...
end

The regular expression is normally delimited by /, which is why the slash within the regular expression is escaped as \/

It is possible to use a different delimiter to avoid having to escape the /:

s =~ %r"1:/2"

You could use other characters than " with this syntax, if you want.

Upvotes: 5

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