ALT a = nil a.upcase # (NoMethodError) a && a.upcase # nil a&.upcase # nil

ALT "abc".frozen? # true "abc" << "d" # "abcd" # warning: literal string will be frozen in the future

ALT require 'date' Date.parse('000102') # #<Date: 2000-01-02 ..> Date.parse('990102') # #<Date: 1999-01-02 ..> Date.parse('680102') # #<Date: 2068-01-02 ..> Date.parse('690102') # #<Date: 1969-01-02 ..> Date.strptime('68-01-02') # #<Date: 0068-01-02 ..> Date.strptime('69-01-02') # #<Date: 0069-01-02 ..>

ALT [2, 3, 1].min # 1 (1..3).max # 3 {b: 1, a: 2, c: 3}.min # [:a, 2] Struct.new(:b, :c).new(2, 3).max # 3 [].min # nil

ALT str = "Hello World!" # one character str.slice(1) # "e" str[1] # "e" str[-1] # "!" str[99] # nil # specific length str[2, 3] # "llo" str[-6, 5] # "World" # range str[2..4] # "llo" str[-6..-2] # "World"

ALT array = 1, 2, 3, 4, 5, 6 # Décomposition d'un tableau a, b = array # a = 1, b = 2 a, *b = array # a = 1, b = [2, 3, 4, 5, 6] a, *b, c = array # a = 1, b = [2, 3, 4, 5], c = 6 *b, c = array # b = [1, 2, 3, 4, 5], c = 6 *a, *b = array # SyntaxError # Merge d'un tableau [0, array, 7, 8] # [0, [1, 2, 3, 4, 5, 6], 7, 8] [0, *array, 7, 8] # [0, 1, 2, 3, 4, 5, 6, 7, 8]

ALT # Mode par défaut est :up en Ruby => le plus éloigné de 0 2.5.round # 3 -2.5.round # -3 # Le mode :down => le plus proche de 0 2.5.round(half: :down) # 2 -2.5.round(half: :down) # -2 # Le mode :even (celui par défaut de Python) => le nombre pair le plus proche (pour une équité statistique) 2.5.round(half: :even) # 2 -2.5.round(half: :even) # -2 3.5.round(half: :even) # 4