CODEWITHSUNDEEP
ruby
taabma
taabma

Reputation: 67

repeated digit in ruby using if clause

I wrote a piece of code to return false when there is a repeated digit in the number passed to the method like this.

no_repeat(2114567) #=> false

The following is the code. I could not find what is wrong with it. Any suggestion to improve this please.

def no_repeat(x)
    x = x.to_s.split('')
    i = 0
    while i < x.length
        if x[i].to_s == x[i + 1]
            false
        end 
        i += 1
    end
    true
end

no_repeat(2114567) #=> true

Upvotes: 3

Views: 143

Answers (3)

Johnson
Johnson

Reputation: 1749

If you want to know if a digit in a number shows up more than once

x.to_s.chars - x.to_s.chars.uniq == 0

If you'd like to know if a digit shows up consecutively in a number you could try this

x.to_s.chars.each_cons(2).to_a.count{|array|array.uniq.length == 1} > 0

Upvotes: 0

Cary Swoveland
Cary Swoveland

Reputation: 110695

def no_repeat(n)
  s = n.to_s
  s.size == s.squeeze.size
end

no_repeat(2114567)  #=> false
no_repeat(-2114567) #=> false
no_repeat(2141567)  #=> true

I suggest you change the method so it returns true when there are repeated digits, and rename it to something like repeated_digits?.

Upvotes: 1

falsetru
falsetru

Reputation: 369194

false does not return function unless it is the last expression of the function; explicitly return it.

def no_repeat(x)
    x = x.to_s.split('')
    i = 0
    while i < x.length
        if x[i].to_s == x[i + 1]
            return false # <--------
        end 
        i += 1
    end
    true
end

no_repeat(2114567)  # => false
no_repeat(1234)     # => true

'12345'.each_char.each_cons(2).any? { |x, y| x == y } false '11345'.each_char.each_cons(2).any? { |x, y| x == y } true

Alternative using regular expression (capturing group, backreference):

def no_repeat(x)
  ! (/(.)\1/ === x.to_s)
end

Another alternative suggested by p11y using each_cons:

'12345'.each_char.each_cons(2).none? { |x, y| x == y }
# => true
'11345'.each_char.each_cons(2).none? { |x, y| x == y }
# => false

'12345'.each_char.each_cons(2).all? { |x, y| x != y }
# => true
'11345'.each_char.each_cons(2).all? { |x, y| x != y }
# => false

Upvotes: 6

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