blocks|key|1101997|text|您指定的代码正在将参数传递给initialize函数。你必须要么使用initialize，要么使用更无聊的语法：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1101998|test+=+Test.new
test.name+=+'Some+test+object'|code-block|syntax|javascript|1101999|entityMap^0|E|A|Y|A|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

The code you're indicating is passing parameters into the <code>initialize</code> function. You will most definitely have to either use <code>initialize</code>, or use a more boring syntax:

<pre><code>test = Test.new
test.name = 'Some test object'
</code></pre>

blocks|key|1102045|text|正如其他人所提到的，最简单的方法是定义一个initialize方法。如果你不想这样做，你可以让你的类继承Struct。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1102046|class+Test+<+Struct.new(:name)
end|code-block|syntax|javascript|1102047|所以现在：|1102048|>>+t+=+Test.new("Some+Test+Object")
=>+#<struct+Test+name="Some+Test+Object">
>>+t.name
=>+"Some+Test+Object"|1102049|entityMap|0|LINK|mutability|MUTABLE|url|http://ruby-doc.org/core/classes/Struct.html^0|L|A|1G|6|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

As mentioned by others, the easiest way to do this would be to define an <code>initialize</code> method. If you don't want to do that, you could make your class inherit from <a href="http://ruby-doc.org/core/classes/Struct.html" rel="noreferrer">Struct</a>.

<pre><code>class Test &lt; Struct.new(:name)
end
</code></pre>

So now:

<pre><code>&gt;&gt; t = Test.new("Some Test Object")
=&gt; #&lt;struct Test name="Some Test Object"&gt;
&gt;&gt; t.name
=&gt; "Some Test Object"
</code></pre>

blocks|key|1317099|text|有一种通过传递带有必要操作的块来执行复杂对象初始化的通用方法。这个块是在要初始化的对象的上下文中计算的，因此您可以轻松地访问所有实例变量和方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1317100|继续你的例子，我们可以定义这个泛型初始化器：|1317101|class+Test
++attr_accessor+:name

++def+initialize(&block)
++++instance_eval(&block)
++end+
end|code-block|syntax|javascript|1317102|然后将相应的代码块传递给它：|1317103|t+=+Test.new+{+@name+=+'name'+}|1317104|或|1317105|t+=+Test.new+do
++self.name+=+'name'
++#+Any+other+initialization+code,+if+needed.
end|1317106|请注意，这种方法本身并不需要向initialize方法添加太多复杂性。|offset|length|style|CODE|1317107|entityMap^0|0|0|0|0|0|0|0|F|A|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|12|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|A|$]]|$1|O|3|P|5|F|7|14|8|@]|9|@]|A|$G|H]]|$1|Q|3|R|5|6|7|15|8|@$S|16|T|17|U|V]]|9|@]|A|$]]|$1|W|3|-4|5|6|7|18|8|@]|9|@]|A|$]]]|X|$]]

There is a general way of doing complex object initialization by
passing a block with necessary actions. This block is evaluated in the
context of the object to be initialized, so you have an easy access to
all instance variables and methods.
Continuing your example, we can define this generic initializer:
<pre><code>class Test
 attr_accessor :name

 def initialize(&amp;block)
 instance_eval(&amp;block)
 end 
end
</code></pre>
and then pass it the appropriate code block:
<pre><code>t = Test.new { @name = 'name' }
</code></pre>
or
<pre><code>t = Test.new do
 self.name = 'name'
 # Any other initialization code, if needed.
end
</code></pre>
Note that this approach does not require adding much complexity
to the <code>initialize</code> method, per se.

blocks|key|1317191|text|需要子类测试(这里显示了自己的方法和初始化器)，例如：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1317192|class+Test
++attr_accessor+:name,+:some_var

++def+initialize+some_var
++++@some_var+=+some_var
++end

++def+some_function
++++"#{some_var}+calculation+by+#{name}"
++end
end

class+SubClassedTest+<+Test
++def+initialize+some_var,+attrbs
++++attrbs.each_pair+do+%7Ck,v%7C
++++++instance_variable_set('@'+%2B+k.to_s,+v)
++++end
++++super(some_var)
++end
end

tester+=+SubClassedTest.new+"some",+name:+"james"
puts+tester.some_function|code-block|syntax|javascript|1317193|输出：some+calculation+by+james|offset|length|style|CODE|1317194|entityMap^0|0|0|3|P|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Would need to subclass Test (here shown with own method and initializer) e.g.:

<pre><code>class Test
 attr_accessor :name, :some_var

 def initialize some_var
 @some_var = some_var
 end

 def some_function
 "#{some_var} calculation by #{name}"
 end
end

class SubClassedTest &lt; Test
 def initialize some_var, attrbs
 attrbs.each_pair do |k,v|
 instance_variable_set('@' + k.to_s, v)
 end
 super(some_var)
 end
end

tester = SubClassedTest.new "some", name: "james"
puts tester.some_function
</code></pre>

outputs: <code>some calculation by james</code>

blocks|key|1317250|text|你可以做到的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1317251|class+Test
+++def+not_called_initialize(but_act_like_one)
++++++++but_act_like_one.each_pair+do+%7Cvariable,value%7C
++++++++++++instance_variable_set('@'+%2B+variable.to_s,+value)
++++++++++++class+<<+self
++++++++++++++++++++self
++++++++++++end.class_eval+do
++++++++++++++++++++attr_accessor+variable
++++++++++++end
++++++++end
+++end
end

(t+=+Test.new).not_called_initialize+:name+=>+"Ashish",+:age+=>+33
puts+t.name+#=>+Ashish
puts+t.age++#=>+33|code-block|syntax|javascript|1317252|一个优点是，您甚至不必使用attr_accessor预先定义实例变量。除了定义getters和setters之外，您还可以通过not_called_initialize方法传递所需的所有实例变量，并让它创建这些变量。|offset|length|style|CODE|1317253|entityMap^0|0|0|D|D|1R|L|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]|$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|V|8|@]|9|@]|A|$]]]|N|$]]

You could do this.

<pre><code>class Test
 def not_called_initialize(but_act_like_one)
 but_act_like_one.each_pair do |variable,value|
 instance_variable_set('@' + variable.to_s, value)
 class &lt;&lt; self
 self
 end.class_eval do
 attr_accessor variable
 end
 end
 end
end

(t = Test.new).not_called_initialize :name =&gt; "Ashish", :age =&gt; 33
puts t.name #=&gt; Ashish
puts t.age #=&gt; 33
</code></pre>

One advantage is that you don't even have to define your instance variables upfront using <code>attr_accessor</code>. You could pass all the instance variables you need through <code>not_called_initialize</code> method and let it create them besides defining the getters and setters.

blocks|key|1317315|text|如果你不想重写initialize，那么你就得向上移动并重写new。下面是一个例子：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1317316|class+Foo
++attr_accessor+:bar,+:baz

++def+self.new(*args,+&block)
++++allocate.tap+do+%7Cinstance%7C
++++++if+args.last.is_a?(Hash)
++++++++args.last.each_pair+do+%7Ck,v%7C
++++++++++instance.send+"#{k}=",+v
++++++++end
++++++else
++++++++instance.send+:initialize,+*args
++++++end
++++end
++end

++def+initialize(*args)
++++puts+"initialize+called+with+#{args}"
++end
end|code-block|syntax|javascript|1317317|如果你最后传入的是一个哈希值，它将绕过initialize，并立即调用setter。如果你传递了任何其他的东西，它将用这些参数调用initialize。|1317318|entityMap^0|7|A|U|3|0|0|J|A|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

If you don't want to override <code>initialize</code> then you'll have to move up the chain and override <code>new</code>. Here's an example:

<pre><code>class Foo
 attr_accessor :bar, :baz

 def self.new(*args, &amp;block)
 allocate.tap do |instance|
 if args.last.is_a?(Hash)
 args.last.each_pair do |k,v|
 instance.send "#{k}=", v
 end
 else
 instance.send :initialize, *args
 end
 end
 end

 def initialize(*args)
 puts "initialize called with #{args}"
 end
end
</code></pre>

If the last thing you pass in is a Hash it will bypass <code>initialize</code> and call the setters immediately. If you pass anything else in it will call initialize with those arguments.

Given the following class:
<pre><code>class Test
 attr_accessor :name
end
</code></pre>
When I create the object, I want to do the following:
<pre><code>t = Test.new {name = 'Some Test Object'}
</code></pre>
At the moment, it results in the <code>name</code> attribute still being <code>nil</code>.
Is that possible without adding an initializer?

How can one set property values when initializing an object in Ruby?

给定以下类：class Test  attr_accessor :nameend创建对象时，我希望执行以下操作：t = Test.new {name = 'Some Test Object'}目前，它导致name属性仍然是nil。在不添加初始化器的情况下可以实现吗？

问如何在Ruby中初始化对象时设置属性值？
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