优雅的码农

摘要： result="str".grep(/re/):如果没有匹配成功则，result.to_s为“”，所以不应使用if "str".grep()来判断是否有成功的匹配，即时没有成功的匹配"str".grep()也是非nil非false的。可以使用=~进行判断，如果没有匹配成功的话"str" =~ /re/会返回nil。 阅读全文

摘要： Instance variables begin with an at sign (@) and can be referenced only within class methods. They differ from local variables in that they don't exist within any particular scope. Instead, a similar variable table is stored for each instance of a class. Instance variables live within a class in 阅读全文