CODEWITHSUNDEEP
ruby
Arif
Arif

Reputation: 1399

Check if a value is less than any value of an array

I have a time-stamp '2016-02-08 16:23:53' and an array containing different time-stamps ['2016-02-09 14:23:53', '2015-02-08 16:23:53', '2016-02-08 16:22:53'].

What is the simplest way to check if the value is less than any of the value in array and return true or false?

Upvotes: 2

Views: 170

Answers (2)

bogl
bogl

Reputation: 1864

Checking if a value is less than any value in an array may be accomplished in Ruby with 

value < array_of_values.min

The simplest way to solve the example given by the OP is

'2016-02-08 16:23:53' < ['2016-02-09 14:23:53', 
                         '2015-02-08 16:23:53', 
                         '2016-02-08 16:22:53'].min

Comparing string representations of dates and times will only work if all strings involved use the same format, the numbers are ordered from big to small (years down to seconds), and the numbers use leading zeros.

The use of adequate data types (like Time or DateTime) instead of strings for storing and processing dates and times will improve the robustness of the software.

Upvotes: 5

Aleksei Matiushkin
Aleksei Matiushkin

Reputation: 121000

If timestamps are strings:

['2016-02-09 14:23:53', '2015-02-08 16:23:53', '2016-02-08 16:22:53'].none? do |ts| 
  Time.parse(ts) > Time.parse('2016-02-08 16:23:53')
end

If timestamps are already instances of Time, there is no need for parse:

timestamps_array.none? do |ts|
  ts > Time.parse('2016-02-08 16:23:53')
end

Well, for the sake of @sawa’s patience :)

It is inefficient to parse the value to compare against each time in the loop:

timestamp_to_check = Time.parse('2016-02-08 16:23:53')
['2016-02-09 14:23:53', '2015-02-08 16:23:53', '2016-02-08 16:22:53'].none? do |ts| 
  Time.parse(ts) > timestamp_to_check
end

Upvotes: 6

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