CODEWITHSUNDEEP
arraysruby
country_dev
country_dev

Reputation: 605

Delete array elements while looping in ruby

I am trying to delete all elements from an array. For example:

@array = [1,2,3,4,5]
@array.each do |element|
  @array.delete(element)
end

Now, I understand why the code above does not work. However, I am tasked with deleting all elements of an array while using this delete_entry method:

def delete_entry(entry)
   @array.delete(entry)
end

I have read that removing elements in the midst of iteration is disallowed by design in ruby. Any ideas as to how I would go about deleting all elements from an array while using the delete_entry method in my implementation?

Upvotes: 0

Views: 1985

Answers (4)

Cary Swoveland
Cary Swoveland

Reputation: 110675

def delete_entry(entry)
  @array.delete(entry)
end

@array = [1,2,3,4,5]

delete_entry(@array.first) until @array.empty?
@array #=> []

I think this reads better than using an enumerator and requires fewer operations when @array contains duplicate values.

Upvotes: 3

steenslag
steenslag

Reputation: 80065

Loop through the array in reverse:

@array = [1,2,3,4,5]
@array.reverse_each do |element|
  @array.delete(element)
end
p @array # => []

Upvotes: 2

7stud
7stud

Reputation: 48599

class Dog
  attr_reader :array

  def initialize
    @array = [1, 2, 3]
  end

  def delete_entry(entry)
     @array.delete(entry)
  end
end


d = Dog.new

d.array.length.times do 
  d.delete_entry(d.array[0])
end

p d.array

--output:--
[]

I have read that removing elements in the midst of iteration is disallowed by design in ruby.

Ridiculous. It just won't work as you may expect. Here's why:

deleting elements from an array while iterating over the array

Upvotes: 1

Prathan Thananart
Prathan Thananart

Reputation: 4077

@array = [1,2,3,4,5]
@_array = @array.clone
@_array.each do |element|
  delete_entry(element)
end

Upvotes: 1

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