blocks|key|1742782|text|不，没有。至少据我所知没有。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1742783|您可以将值assign+part+(owner+=+search.getOwner())放入if部分，但User+owner声明必须独立。|offset|length|style|CODE|1742784|entityMap^0|0|H|R|1G|A|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@$D|L|E|M|F|G]|$D|N|E|O|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|I|$]]

No, there isn't. As far as I know at least.

You may put the value assign part <code>(owner = search.getOwner())</code> into the if part, but the <code>User owner</code> declaration must be on its own.

blocks|key|1742811|text|在您的代码中，所有者在if条件的作用域中被本地声明。尝试此代码修改|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1742812|User+owner+=+null;
if+((owner+=+(User)search.getOwner())+instanceof+User+&&+owner.getId()+!=+null)+{
++++++++searchQuery.append("owner_id+=+:ownerId+AND+");
++++++++queryMap.put("ownerId",+owner.getId());
++++}|code-block|syntax|javascript|1742813|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

In Your code owner is declared locally in the scope of if condition. Try this code modification

<pre><code>User owner = null;
if ((owner = (User)search.getOwner()) instanceof User &amp;&amp; owner.getId() != null) {
 searchQuery.append("owner_id = :ownerId AND ");
 queryMap.put("ownerId", owner.getId());
 }
</code></pre>

blocks|key|2119128|text|下面的代码有什么问题，在我看来，它更具可读性？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2119129|User+owner+=+search.getOwner();
if+(owner+instanceof+User+&&+owner.getId()+!=+null)+{
++++searchQuery.append("owner_id+=+:ownerId+AND+");
++++queryMap.put("ownerId",+owner.getId());
}|code-block|syntax|javascript|2119130|正如注释中所提到的，要么getOwner返回一个用户，并且不需要instanceof测试，要么它不需要，在这种情况下，您可以编写：|offset|length|style|CODE|2119131|Object+owner+=+search.getOwner();
if+(owner+instanceof+User+&&+(User)+owner.getId()+!=+null)+{
++++searchQuery.append("owner_id+=+:ownerId+AND+");
++++queryMap.put("ownerId",+(User)+owner.getId());
}|2119132|entityMap^0|0|0|W|A|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

What's wrong with the following code, which in my view is much more readable?

<pre><code>User owner = search.getOwner();
if (owner instanceof User &amp;&amp; owner.getId() != null) {
 searchQuery.append("owner_id = :ownerId AND ");
 queryMap.put("ownerId", owner.getId());
}
</code></pre>

as mentioned in the comments, either getOwner returns a User and there is no need for the <code>instanceof</code> test, or it doesn't in which case you could write:

<pre><code>Object owner = search.getOwner();
if (owner instanceof User &amp;&amp; (User) owner.getId() != null) {
 searchQuery.append("owner_id = :ownerId AND ");
 queryMap.put("ownerId", (User) owner.getId());
}
</code></pre>

blocks|key|98576|text|在Java中，Asssignment是一个ExpressionStatement，而if条件只接受一个表达式。请参阅权威来源的Java+Language+Specification。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|98577|entityMap|0|LINK|mutability|MUTABLE|url|http://docs.oracle.com/javase/specs/jls/se5.0/html/statements.html#5991^0|1R|R|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]]]]

Asssignment in Java is an ExpressionStatement, whereas the if condition accepts only an Expression. See the <a href="http://docs.oracle.com/javase/specs/jls/se5.0/html/statements.html#5991" rel="nofollow">Java Language Specification</a> for the authoritative source.

In java I'm trying to use shorthand variable assignment like below. Currently <code>owner</code> is assigned on a different line but I'd like to put it on the same line as below. This isn't working - is it not possible or is there another route?

<pre><code> if ((User owner = search.getOwner()) instanceof User &amp;&amp; owner.getId() != null) {
 searchQuery.append("owner_id = :ownerId AND ");
 queryMap.put("ownerId", owner.getId());
 }
</code></pre>

Thanks

shorthand variable assignment

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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在java中，我尝试使用速记变量赋值，如下所示。目前，owner被分配到不同的行，但我想把它放在同一行，如下所示。这不起作用--这是不可能的，还是有其他方法？    if ((User owner = search.getOwner()) instanceof User && owner.getId() != null...

问速记变量赋值
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