blocks|key|769004|text|你在找Object.tap吗？|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|769005|entityMap|0|LINK|mutability|MUTABLE|url|http://ruby-doc.org/core/classes/Object.src/M001035.html^0|3|A|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

Are you looking for <a href="http://ruby-doc.org/core/classes/Object.src/M001035.html" rel="nofollow">Object.tap</a> ?

blocks|key|552379|text|我不知道有这样一个内置的东西，但你可以很容易地自己做：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|552380|class+Object
++def+something(&block)
++++block.call(self)
++end
end

p+"foo".something+{+%7C+o+%7C+[o]+}
p+23.something+{+%7C+x+%7C+p+x;+42+}|code-block|syntax|javascript|552381|给出|552382|["foo"]++++++#+object+"foo"+put+into+an+array
23+++++++++++#+object+handed+to+block
42+++++++++++#+something+return+block's+result|552383|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

I don't know of such a thing built-in but you can easily do it yourself:

<pre><code>class Object
 def something(&amp;block)
 block.call(self)
 end
end

p "foo".something { | o | [o] }
p 23.something { | x | p x; 42 }
</code></pre>

gives 

<pre><code>["foo"] # object "foo" put into an array
23 # object handed to block
42 # something return block's result
</code></pre>

blocks|key|552419|text|我有时希望在标准库中有一个类似的函数。例如，该名称可以是with或with_it|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|552420|(用新名称重复以前的代码)|552421|class+Object
++def+with_it(&block)
++++block.call(self)
++end
end|code-block|syntax|javascript|552422|示例用法：|552423|x+=+[1,+2,+3,+4,+5].map+{%7Cx%7C+x+*+x+}.with_it+do+%7Clist%7C
+++head+=+list.unshift
+++list+<<+head+*+10
+++list.join+"+/+"
end|552424|与此相对的是：|552425|list+=+[1,+2,+3,+4,+5].map+{%7Cx%7C+x+*+x+}
head+=+list.unshift
list+<<+head+*+10
x+=+list.join+"+/+"|552426|虽然后者更容易理解，但前者的好处是保持变量list和head的作用域，而且在我看来，对x的赋值更加清晰(对x的赋值必须插入到代码的最后一行)。如果代码是更大方法的一部分，作用域将是一个优势。|552427|因此，使用with_it的另一种选择是将代码放在单独的方法中。例如：|552428|def+mult_head_and_join(list)
++++head+=+list.unshift
++++list+<<+head+*+10
++++list.join+"+/+"
end

x+=+mult_head_and_join+[1,+2,+3,+4,+5].map+{%7Cx%7C+x+*+x+}|552429|我不确定在这里得出什么结论，但我想我会投票支持将with_it包含在标准库中|552430|entityMap^0|S|4|X|7|0|0|0|0|0|0|0|L|4|Q|4|17|1|1H|1|0|5|7|0|0|0^^$0|@$1|2|3|4|5|6|7|14|8|@$9|15|A|16|B|C]|$9|17|A|18|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|19|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|1A|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1B|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|1C|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1D|8|@]|D|@]|E|$]]|$1|S|3|T|5|J|7|1E|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|1F|8|@$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]]|D|@]|E|$]]|$1|W|3|X|5|6|7|1O|8|@$9|1P|A|1Q|B|C]]|D|@]|E|$]]|$1|Y|3|Z|5|J|7|1R|8|@]|D|@]|E|$K|L]]|$1|10|3|11|5|6|7|1S|8|@]|D|@]|E|$]]|$1|12|3|-4|5|6|7|1T|8|@]|D|@]|E|$]]]|13|$]]

I sometimes wish for a similar function in the standard library. The name could for example be <code>with</code> or <code>with_it</code>

(Repeating previous code with new name)

<pre><code>class Object
 def with_it(&amp;block)
 block.call(self)
 end
end
</code></pre>

Example usage:

<pre><code>x = [1, 2, 3, 4, 5].map {|x| x * x }.with_it do |list|
 head = list.unshift
 list &lt;&lt; head * 10
 list.join " / "
end
</code></pre>

As opposed to:

<pre><code>list = [1, 2, 3, 4, 5].map {|x| x * x }
head = list.unshift
list &lt;&lt; head * 10
x = list.join " / "
</code></pre>

While the latter is easier to understand, the former has the benefit of keeping the variables <code>list</code> and <code>head</code> scoped and the assignment to <code>x</code> is more clear in my opinion (the assignment to <code>x</code> has to be inserted into the last line of the code). Scoping would be a benfit if the code was a part of a larger method.

Another option to using <code>with_it</code> would thus be putting the code in a separate method. Eg:

<pre><code>def mult_head_and_join(list)
 head = list.unshift
 list &lt;&lt; head * 10
 list.join " / "
end

x = mult_head_and_join [1, 2, 3, 4, 5].map {|x| x * x }
</code></pre>

Not sure what to conclude with here, but I guess I'd vote for with_it to be included in the standard library

Is there a method in Ruby that returns the content of the block passed on to an object?

For example, what if I have an object which I want to put in an array?

In an ideal world, we would do (what I'm looking for):

<pre><code>"string".reverse.upcase.something{ |s| send(s) }
</code></pre>

which would return an array with my object, as equivalent to:

<pre><code>send("string".reverse.upcase)
</code></pre>

which isn't chainable if I have my object to start with and can get messy in more complex scenarios.

So the <code>something</code> method would return the evaluation of the block, like <a href="http://ruby-doc.org/core/classes/Array.html#M000249" rel="nofollow"><code>Array#map</code></a>, but for one element only.

Method that returns the yield for an object in Ruby

Ruby中有没有一个方法可以返回传递给对象的块的内容？例如，如果我有一个想要放入数组中的对象，该怎么办？在理想的情况下，我们会这样做(我正在寻找的)："string".reverse.upcase.something{ |s| send(s) }它将返回一个包含我的对象的数组，等同于：send("string".rev...

问方法，该方法返回Ruby中对象的收益率
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