CODEWITHSUNDEEP
rubydatetimetime
Paul
Paul

Reputation: 26660

Time.now vs Time.new in Ruby

Is there some difference between Time.now and Time.new (without parameters)? May be difference in memory management or some small details?

Upvotes: 3

Views: 2130

Answers (3)

Natan Rubinstein
Natan Rubinstein

Reputation: 665

Using Ruby 2.4.1 and Rails 5.0.3 When using travel_to in tests Time.new does not get affected by it but Time.now does change because of it

Upvotes: 1

Surya
Surya

Reputation: 16012

now is an alias for new. There's no difference between them. Jeff price's get to answer(and his answer is also correct, please up vote his answer if you like this) first, because I was writing and running this benchmark:

Ruby 2.1.2(MRI):

Rehearsal ----------------------------------------------------------------------------
Time.new                                   0.670000   0.000000   0.670000 (  0.679709)
Time.now                                   0.880000   0.010000   0.890000 (  0.881899)
------------------------------------------------------------------- total: 1.560000sec

                                               user     system      total        real
Time.new                                   0.720000   0.000000   0.720000 (  0.719453)
Time.now                                   0.740000   0.010000   0.750000 (  0.742711)

Rehearsal ----------------------------------------------------------------------------
Time.new                                   0.810000   0.000000   0.810000 (  0.811874)
Time.now                                   0.830000   0.000000   0.830000 (  0.831346)
------------------------------------------------------------------- total: 1.640000sec

                                               user     system      total        real
Time.new                                   0.790000   0.010000   0.800000 (  0.800082)
Time.now                                   0.740000   0.000000   0.740000 (  0.749995)

Rehearsal ----------------------------------------------------------------------------
Time.new                                   0.680000   0.010000   0.690000 (  0.690337)
Time.now                                   0.850000   0.000000   0.850000 (  0.856800)
------------------------------------------------------------------- total: 1.540000sec

                                               user     system      total        real
Time.new                                   0.790000   0.010000   0.800000 (  0.792666)
Time.now                                   0.770000   0.000000   0.770000 (  0.777414)

Rehearsal ----------------------------------------------------------------------------
Time.new                                   0.590000   0.010000   0.600000 (  0.594650)
Time.now                                   0.710000   0.010000   0.720000 (  0.717067)
------------------------------------------------------------------- total: 1.320000sec

                                               user     system      total        real
Time.new                                   0.870000   0.000000   0.870000 (  0.872646)
Time.now                                   0.680000   0.010000   0.690000 (  0.687092)

Rehearsal ----------------------------------------------------------------------------
Time.new                                   0.780000   0.010000   0.790000 (  0.786419)
Time.now                                   0.780000   0.000000   0.780000 (  0.789049)
------------------------------------------------------------------- total: 1.570000sec

                                               user     system      total        real
Time.new                                   0.760000   0.010000   0.770000 (  0.768194)
Time.now                                   0.790000   0.010000   0.800000 (  0.790981)

Run benchmark yourself:

n = 1000000

5.times do 
  Benchmark.bmbm(40) do |x|
    x.report("Time.new"){ n.times { Time.new } }
    x.report("Time.now"){ n.times { Time.now } }
  end
end

Upvotes: 7

Jeff Price
Jeff Price

Reputation: 3229

There is no difference.

Time.now is an alias for ::new. Returns a Time object initialized to the current system time.

http://www.ruby-doc.org/core-2.1.4/Time.html#method-c-now

Upvotes: 12

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