blocks|key|385191|text|如果retry的值为1，则id为true，否则retry为false。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|385192|entityMap^0|2|5|D|2|G|4|N|5|T|5|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

<code>retry</code> is <code>true</code> if <code>id</code> has the value 1, otherwise <code>retry</code> is <code>false</code>.

blocks|key|385428|text|id+==+1是一个布尔表达式，如果id等于1，则为true，否则为false。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|385429|boolean+retry+=+id+==+1;声明了一个名为retry的布尔变量，并将布尔表达式id+==+1的值赋给该变量。|385430|所以它声明了一个布尔变量，如果为id+==+1，则为true，否则为false。|385431|为了让它更清楚一点，你可以这样写：|385432|boolean+retry+=+(id+==+1);|code-block|syntax|javascript|385433|entityMap^0|0|7|I|2|M|1|0|0|O|V|5|1D|7|0|G|7|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|19|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1A|8|@]|D|@]|E|$O|P]]|$1|Q|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|R|$]]

<code>id == 1</code> is a boolean expression which is true if <code>id</code> equals <code>1</code>, and false otherwise. 

<code>boolean retry = id == 1;</code> declares a boolean variable named <code>retry</code>, and assigns the value of the boolean expression <code>id == 1</code> to this variable.

So it declares a boolean variable which is true if <code>id == 1</code>, and false otherwise.

To make it a bit clearer, you might write it that way:

<pre><code>boolean retry = (id == 1);
</code></pre>

blocks|key|385213|text|与以下内容相同|type|unstyled|depth|inlineStyleRanges|entityRanges|data|385214|boolean+retry;
if+(id+==+1)
+++retry+=+true;
else
+++retry+=+false;|code-block|syntax|javascript|385215|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|$]]

It is the same as

<pre><code>boolean retry;
if (id == 1)
 retry = true;
else
 retry = false;
</code></pre>

blocks|key|167596|text|与赋值运算符=相比，作为相等谓词的==具有更高的优先级。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167597|因此，首先计算id+==+1，然后将其值(+true或false)赋给retry。|167598|entityMap^0|6|1|H|2|0|7|7|Z|5|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|I|$]]

<code>==</code>, which is the equality predicate, has a higher precedence than <code>=</code>, which is the assignment operator.

Therefore, <code>id == 1</code> is evaluated first and then its value (either true or false) is assigned to <code>retry</code>.

blocks|key|167287|text|如果为id+==+1，则布尔重试将获得TRUE值。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167288|等同于：|167289|boolean+retry;
if+(id+==+1)+{
++++retry+=+true;
}+else+{
++++retry+=+false;
}|code-block|syntax|javascript|167290|entityMap^0|3|7|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|R|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|S|8|@]|D|@]|E|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|D|@]|E|$]]]|N|$]]

The boolean retry gets the value of true if <code>id == 1</code>.

It's the same as:

<pre><code>boolean retry;
if (id == 1) {
 retry = true;
} else {
 retry = false;
}
</code></pre>

blocks|key|167351|text|首先，id的计算结果为1，因此id可能是一个integer。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167352|在此之后，赋值为retry，因此如果id等于1，则retry将变为true，而对于id的任何其他值，retry将变为false。|167353|entityMap^0|3|2|F|2|M|7|0|8|5|I|2|P|5|X|4|15|2|1E|5|1M|5|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Q|8|@$9|R|A|S|B|C]|$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|H|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|I|$]]

first the <code>id</code> is evaluated with 1, so presumably <code>id</code> is an <code>integer</code>.

After that, the value <code>retry</code> is assigned this evaluation, so if <code>id</code> is equal to 1, <code>retry</code> will become <code>true</code>, and for any other value of <code>id</code> <code>retry</code> will become <code>false</code>.

blocks|key|167508|text|此行创建一个布尔变量，如果id等于1，则将其设置为true，如果不等于1，则设置为false。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167509|entityMap^0|D|2|P|4|15|5|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

This line creates a boolean variable and sets it to <code>true</code> if <code>id</code> is equal to 1 and <code>false</code> if it is not.

blocks|key|167575|text|它的行为类似于三元运算，C中的(x)+?+true+:+false，C%2B%2B，C#等等；|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167576|类似的语法：|167577|boolean+retry+=+(id+==+1)?+true:+false;+|code-block|syntax|javascript|167578|或者它可以用另一种方式写成：|167579|boolean+retry;
if+(id+==+1)+{
++++retry+=+true;
}+else+{
++++retry+=+false;
}|167580|entityMap^0|F|I|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|V|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|W|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|X|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|Y|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|R|$]]

It is acts like a ternary operation, <code>(x) ? true : false</code> in C, C++, C#, etc;

The similar syntax:

<pre><code>boolean retry = (id == 1)? true: false; 
</code></pre>

Or it can written another way:

<pre><code>boolean retry;
if (id == 1) {
 retry = true;
} else {
 retry = false;
}
</code></pre>

blocks|key|167651|text|我发现仅仅使用括号就可以帮助理清像这样的复杂语句背后的困惑。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|167652|boolean+retry+=+(id+==+1);对我来说更有意义。很明显，(id+==+1)是一个被计算的表达式，结果被赋值给boolean+retry|offset|length|style|CODE|167653|entityMap^0|0|0|Q|13|9|1T|D|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]|$D|N|E|O|F|G]|$D|P|E|Q|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|R|8|@]|9|@]|A|$]]]|I|$]]

I find that just using parens helps to clear up the confusion behind complex statements like this. 

<code>boolean retry = (id == 1);</code> Makes much more sense to me. Here it's clear that <code>(id == 1)</code> is an expression being evaluated and the result is being assigned to <code>boolean retry</code>

blocks|key|167546|text|它是一种定义布尔变量的方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|167547|当id为1时，retry的值将为true。|offset|length|style|CODE|167548|entityMap^0|0|1|2|4|1|7|5|G|4|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]|$D|N|E|O|F|G]|$D|P|E|Q|F|G]|$D|R|E|S|F|G]]|9|@]|A|$]]|$1|H|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|I|$]]

It is a way of defining a boolean variable.

When <code>id</code> is <code>1</code>, the value of <code>retry</code> will be <code>true</code>.

blocks|key|385639|text|由于retry是一个boolean，因此retry分配一个表达式，该表达式将是true或false。此外，将首先求解==，然后将其分配给retry。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|385640|entityMap^0|2|5|A|7|K|5|1M|2|1W|5|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

<code>retry</code> assigns an expression which will be either true or false as <code>retry</code> is a <code>boolean</code>.
Further, <code>==</code> will be solved first and then it will be assigned to <code>retry</code>.

blocks|key|167670|text|如果你这样看，可能会更容易看到发生了什么：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|167671|boolean+retry+=+(id+==+1);|code-block|syntax|javascript|167672|所以基本上它会检查id是否等于1，然后将结果赋给变量retry。|167673|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

It might be easier to see whats happening if you look at it like this:

<pre><code>boolean retry = (id == 1);
</code></pre>

So basically it checks if id equals 1, and then assigns the result to the variable retry.

blocks|key|167675|text|它与retry+=+(id+==+1)基本相同。它正在计算布尔表达式，并将其赋给retry。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|167676|entityMap^0|2|H|14|5|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

It is basically the same as <code>retry = (id == 1)</code>. It is evaluating the boolean expression, and assigning it to <code>retry</code>.

blocks|key|385734|text|布尔变量retry将获得值0或1，具体取决于表达式id==1返回的是true还是false。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|385735|如果id的值为1，则id==1将对应于true，因此为retry=1。|385736|如果id的值为0，则id==1将对应于false，因此为retry=0。|385737|请注意，==是一个比较运算符。|385738|entityMap^0|4|5|D|1|F|1|P|5|Y|4|14|5|0|2|2|7|1|A|5|J|4|R|7|0|2|2|7|1|A|5|J|5|S|7|0|4|2|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]|$9|S|A|T|B|C]|$9|U|A|V|B|C]|$9|W|A|X|B|C]|$9|Y|A|Z|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]|$9|15|A|16|B|C]|$9|17|A|18|B|C]|$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1B|8|@$9|1C|A|1D|B|C]|$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]|$9|1K|A|1L|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|1M|8|@$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|L|3|-4|5|6|7|1P|8|@]|D|@]|E|$]]]|M|$]]

The Boolean variable <code>retry</code> will get value <code>0</code> or <code>1</code> depending on whether the expression <code>id==1</code> returns <code>true</code> or <code>false</code>.

If value of <code>id</code> is <code>1</code>, then <code>id==1</code> will correspond to <code>true</code>, thus <code>retry=1</code>.

And if value of <code>id</code> is <code>0</code>, then <code>id==1</code> will correspond to <code>false</code>, thus <code>retry=0</code>.

Please note that <code>==</code> is a comparison operator.

blocks|key|167689|text|1.int+id+=+1;
++boolean+retry+=+id+==+1;|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|167690|也就是说retry+=+true;。|unstyled|offset|length|style|CODE|167691|2.int+id+=+2;
++boolean+retry+=+id+==+1;|167692|也就是说retry+=+false;。|167693|简化id+==+1可以认为是|167694|if+(+id+==+1+){
}|167695|entityMap^0|0|4|D|0|0|4|E|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|V|8|@$G|W|H|X|I|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|Y|8|@]|9|@]|A|$B|C]]|$1|M|3|N|5|F|7|Z|8|@$G|10|H|11|I|J]]|9|@]|A|$]]|$1|O|3|P|5|F|7|12|8|@]|9|@]|A|$]]|$1|Q|3|R|5|6|7|13|8|@]|9|@]|A|$B|C]]|$1|S|3|-4|5|F|7|14|8|@]|9|@]|A|$]]]|T|$]]

<pre><code>1.int id = 1;
 boolean retry = id == 1;
</code></pre>

which means <code>retry = true;</code>.

<pre><code>2.int id = 2;
 boolean retry = id == 1;
</code></pre>

which means <code>retry = false;</code>.

Simplification id == 1 can be consider as

<pre><code>if ( id == 1 ){
}
</code></pre>

blocks|key|385774|text|代码可以像这样写，然后就很容易理解了，你这样认为吗？最后，感谢您给我回答这个问题的机会！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|385775|boolean+retry+=+(id+==+1);|code-block|syntax|javascript|385776|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|$]]

The code can write just like this,then it will be understood easily,do you think
so? Last, thanks you for giving the chance to answer the question!

<pre><code>boolean retry = (id == 1);
</code></pre>

I have been learning Java for a while now and still learning new syntax tricks and stuff. I came across this in Android source code:

<pre><code>boolean retry = id == 1;
</code></pre>

What does it mean?

What does this line mean in Java: boolean retry = id == 1;

Android

Java

我学习Java已经有一段时间了，并且还在学习新的语法技巧和东西。我在Android源代码中遇到了这样的情况：boolean retry = id == 1;什么意思？

问这一行在Java中是什么意思: boolean retry = id == 1；
EN

回答 16

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问这一行在Java中是什么意思: boolean retry = id == 1；EN

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问这一行在Java中是什么意思: boolean retry = id == 1；
EN