=begin 條件判斷語句包括if語句,unless語句,case語句, =end #if 語句 =begin if 條件 then 處理1 elsif 條件2 then 處理2 else 處理3 end =end a = 10 b = 20 if a > b puts "a bigger than b" elsif a < b puts "a smaller than b" else puts "a is equal to b" end puts "a bigger than b" if a > b #unless 語句,與if語句相反,條件判斷爲假的時執行處理 =begin unless 條件 處理1 else 處理2 end =end a = 10 b = 20 unless a > b puts "a smaller/same as than b" end #case 語句,適用於比較的對象只有一個的時候,根據這個對象的值不同,執行不同的處理;when可以一次指定多個值 =begin case 比較對象 when 值1 then 處理1 when 值2 then 處理2 when 值3 then 處理3 else 處理4 end =end tags = ["A", "IMG", "PRE"] tags.each do |word| case word when "P", "A", "I", "B", "BLOCKQUOTE" puts "#{word} has child." when "IMG", "BR" puts "#{word} has child." else puts "#{word} cannoot be used" end end array = ["a", 1, nil] array.each do |word| case word when String puts "the word is a String" when Numeric puts "the word is a Numeric" else puts "other words are Something" end end text.each_line do |line| case line when /^From:/i puts "find a sender" when /^To:/i puts "find a receiver" when /^$/ puts "resolution are finnished" exit else break end end
Ruby-條件判斷
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