详解ruby的attr_accessor和cattr_accessor
1. attr_accessor的用法相当简单, 就相当于getter和setter,看一个类就知道怎样用了:
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class Test attr_accessor :name def initialize()@name = "yanzilee9292" endend#testputs Test.new.name
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保存这个类为test.rb文件, 通过命令行运行 ruby test.rb, 会得到以下结果:
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2. 如果我们把attr_accessor去掉, 该怎么输出name的值呢
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class Test def initialize()@name ="yanzilee9292" end #test puts Test.new.instance_eval {@name}end?
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可以看到, 用attr_accessor会把事情变得更加简单
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3. cattr_accessor和attr_accessor的区别
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cattr_accessor就相当于java的类静态变量, 对所有的类实例共享
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class Counter cattr_accessor :class_count attr_accessor :instance_countend counter1 = Counter.newcounter1.instance_count = 1counter1.class_count = 1 counter2 = Counter.newp counter2.instance_count#> nilp counter2.class_count#> 1?
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