29 lines
831 B
Plaintext
29 lines
831 B
Plaintext
import java.util.ArrayList
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import java.util.HashMap
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# booleans
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puts 'true is true' if true
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puts 'false is false' if (!false)
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# lists treated as booleans
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x = ArrayList.new
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puts "empty array is true" if x
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x.add("an element")
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puts "full array is true" if x
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puts "isEmpty() is false" if !x.isEmpty()
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# maps treated as booleans
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map = HashMap.new
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puts "empty map is true" if map
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map.put('a', '1')
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puts "full map is true" if map
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puts "size() is 0 is false" if !(map.size() == 0)
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# these things do not compile
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# value = nil # ==> cannot assign nil to Boolean value
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# puts 'nil is false' if false == nil # ==> cannot compare boolean to nil
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# puts '0 is false' if (0 == false) # ==> cannot compare int to false
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#puts 'TRUE is true' if TRUE # ==> TRUE does not exist
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#puts 'FALSE is false' if !FALSE # ==> FALSE does not exist
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