Created
September 17, 2012 19:29
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Adding Array#average with tests
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| class Array | |
| def not_empty? | |
| !self.empty? | |
| end | |
| def average | |
| temp = self.compact | |
| temp.map! {|e| e.is_a?(String) && (e.match(/\d/)) ? e.to_f : e} | |
| return nil if (temp.not_empty?) && (temp.reject! {|e| !e.is_a? Numeric}; temp.empty?) | |
| return 0.0 if temp.empty? | |
| temp.inject(:+) / temp.length.to_f | |
| end | |
| end | |
| #Tests | |
| describe Array do | |
| describe "#not_empty" do | |
| it 'should return true for an Array with more than zero elements' do | |
| [1,2].not_empty?.should be_true | |
| end | |
| it 'should return false for an Array with zero elements' do | |
| [].not_empty?.should be_false | |
| end | |
| end | |
| describe "#average" do | |
| it 'should return 5 for [1..9]' do | |
| (1..9).to_a.average.should eq(5) | |
| end | |
| it 'should return 5.5 for [1..10]' do | |
| (1..10).to_a.average.should eq(5.5) | |
| end | |
| it 'should return 0.0 for [nil]' do | |
| [nil].average.should eq(0.0) | |
| end | |
| it 'should return 0.0 for []' do | |
| [].average.should eq(0.0) | |
| end | |
| it 'should not alter original Array' do | |
| a = [1, 2, 3, nil, 5, nil] | |
| original_length = a.length | |
| a.average | |
| a.length.should eq(original_length) | |
| end | |
| it 'should return nil for [String, String, String]' do | |
| %W(Nothing but Strings).average.should be_nil | |
| end | |
| it 'should return 5 for [1..9, String, String]' do | |
| a = (1..9).to_a | |
| a += %W(Some added strings) | |
| a.average.should eq(5) | |
| end | |
| it 'should return 5 for ["1".."9"]' do | |
| ('1'..'9').to_a.average.should eq(5) | |
| end | |
| it 'should return 5 for ["1".."9", String, String]' do | |
| a = ('1'..'9').to_a | |
| a += %W(Some added strings) | |
| a.average.should eq(5) | |
| end | |
| end | |
| end |
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