comparing two strings in ruby

Question

I've just started to learn ruby and this is probably very easy to solve. How do I compare two strings in Ruby?

I've tried the following :

puts var1 == var2 //false, should be true (I think)
puts var1.eql?(var2) //false, should be true (I think)

When I try to echo them to console so I can compare values visually, I do this :

puts var1 //prints "test content" without quotes
puts var2 //prints ["test content"] with quotes and braces

Ultimately are these different types of strings of how do I compare these two?

possible duplicate of [Comparing Strings in Ruby](http://stackoverflow.com/questions/426159/comparing-strings-in-ruby) — JaredMcAteer, Dec 11 '12 at 18:03

tokhi · Answer 1 · 2012-12-11T16:51:16.180

109

Here are some:

"Ali".eql? "Ali"
=> true

The spaceship (<=>) method can be used to compare two strings in relation to their alphabetical ranking. The <=> method returns 0 if the strings are identical, -1 if the left hand string is less than the right hand string, and 1 if it is greater:

"Apples" <=> "Apples"
=> 0

"Apples" <=> "Pears"
=> -1

"Pears" <=> "Apples"
=> 1

A case insensitive comparison may be performed using the casecmp method which returns the same values as the <=> method described above:

"Apples".casecmp "apples"
=> 0

edited Dec 11 '12 at 16:51

answered Dec 11 '12 at 16:45

tokhi

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How do we do a comparison by ignoring the case ? – stack1 Jan 23 '15 at 18:34
@stack1 "Apples".to_lower <=> "apples".to_lower – dev_row Feb 17 '15 at 15:00
Will this work with strings like 'a+', 'a', and 'a-'? – SirFunkButter Jul 26 '18 at 13:42

AShelly · Accepted Answer · 2013-09-30T14:13:52.670

From what you printed, it seems var2 is an array containing one string. Or actually, it appears to hold the result of running .inspect on an array containing one string. It would be helpful to show how you are initializing them.

irb(main):005:0* v1 = "test"
=> "test"
irb(main):006:0> v2 = ["test"]
=> ["test"]
irb(main):007:0> v3 = v2.inspect
=> "[\"test\"]"
irb(main):008:0> puts v1,v2,v3
test
test
["test"]

score 7 · Answer 3 · answered Dec 11 '12 at 16:36

7

var1 is a regular string, whereas var2 is an array, this is how you should compare (in this case):

puts var1 == var2[0]

answered Dec 11 '12 at 16:36

Zbigniew

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or `var2.first` or `var2.shift`. – the Tin Man Dec 11 '12 at 17:00
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If you want to be agnostic on type, `[*var1].join == [*var2].join` – histocrat Dec 11 '12 at 17:10
@histocrat Assuming the array has a single element or you're trying to compare a single string with an array of strings, your comment makes sense. Those aren't very typical operations, though. – Anthony Aug 06 '15 at 20:45

score 6 · Answer 4 · answered Dec 11 '12 at 16:36

6

Comparison of strings is very easy in Ruby:

v1 = "string1"
v2 = "string2"
puts v1 == v2 # prints false
puts "hello"=="there" # prints false
v1 = "string2"
puts v1 == v2 # prints true

Make sure your var2 is not an array (which seems to be like)

answered Dec 11 '12 at 16:36

p.matsinopoulos

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comparing two strings in ruby

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