hackerrank question - use of proc in ruby-CodePudding

problem: Create a Proc p that will check whether a given array of elements are nil or not. Use .nil? to evaluate elements. Print 'true' if elements are nil, and 'false' if the elements has a value

Issue: I came up with below solution but its giving me only one value as true instead of checking for each value of array , please help in correcting below code:

Code:

def check_nill(array1)

p = Proc.new{ |num| num.nil?}

c = array1.any?(&p)

return c

end

array1 = [2,nil,8]

result = check_nill(array1)

puts "#{ result1 }"

Output: true

CodePudding user response：

Create a Proc to check if a value is a nil or not.

my_proc = Proc.new { |num| num.nil? }

Iterate over the array using the above proc

array1 = [2,nil,8]
array1.map { |x| my_proc.call(x) }

You will get the below result

[false, true, false]

CodePudding user response：

Your solution doesn't work because the method you're using, Array#any?, returns true if any of the values in the array is nil (due to your p). What I understood is that you want a solution that will return if each element is nil or not.

A possible solution is:

# You can create a Proc `p` that'll map an array to the results of `nil?`.
p = Proc.new { |ary| ary.map(&:nil?) } 

# You can apply a Proc by using the method `call`, or by doing:
#   p.([1, nil, 2])
#   p[[1, nil, 2]]
p.call([1, nil, 2]) # => [false, true, false]