blocks|key|2204330|text|你应该改变比较长度和比较单个特征的顺序:如果长度不同，就没有必要比较其余的！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2204331|一旦你知道有差异，你也应该返回false+-同样，继续循环的唯一原因是如果你认为你可能会返回true。|offset|length|style|CODE|2204332|下面是如何更改程序的方法：|2204333|public+boolean+equals+(FeatureVector+x+)
{
++++if+(this.features.length+!=+x.features.length+)+{
++++++++return+false;
++++}
++++//+If+we+get+here,+the+sizes+are+the+same:
++++for+(int+i+=+0+;+i+<+this.features.length+;+i%2B%2B)
++++{
++++++++if+(this.features[i]+!=+x.features[i]+)+{
++++++++++++return+false;
++++++++}
++++}
++++//+If+we+got+here,+the+sizes+are+the+same,+and+all+elements+are+also+the+same:
++++return+true;+
}|code-block|syntax|javascript|2204334|entityMap^0|0|F|5|1A|4|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]|$D|U|E|V|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|W|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|X|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

You should switch the order of comparing the length and comparing the individual features: if the lengths are different, there's no point of comparing the rest!

You should also return <code>false</code> as soon as you know there's a difference - again, the only reason to continue with the loop is if you think that you may return <code>true</code>.

Here is how you can change your program:

<pre><code>public boolean equals (FeatureVector x )
{
 if (this.features.length != x.features.length ) {
 return false;
 }
 // If we get here, the sizes are the same:
 for (int i = 0 ; i &lt; this.features.length ; i++)
 {
 if (this.features[i] != x.features[i] ) {
 return false;
 }
 }
 // If we got here, the sizes are the same, and all elements are also the same:
 return true; 
}
</code></pre>

blocks|key|2204368|text|初始代码中的错误是将result初始化为false。这导致循环在第一次比较之前立即退出。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2204369|注意，将布尔值与true和false进行比较被认为是一种不太好的做法。充其量，它是多余的。在最坏的情况下，您可能会创建一个很难发现的错误：|2204370|if+(some_value+=+false)+{++//+DON'T+do+this+--+it's+always+false!|code-block|syntax|javascript|2204371|在此之前，我已经建议，如果你一定要这样做，可能是因为未诊断的心理状况或一个真正应该在管理中的技术领导，通过使用Yoda条件来保护自己：|2204372|if+(false+==+some_value)+{++//+Syntax+error,+a+single+"="+will+create.|2204373|2204374|以下是原始代码的更正和优化版本：|2204375|public+boolean+equals+(FeatureVector+x)+{

++//+Do+the+"cheapest"+test+first,+so+you+have+an+opportunity+to+return
++//+without+waiting+for+the+loop+to+run.
++if+(this.features.length+!=+x.features.length)+{
+++++return+false;
++}

++//+There's+no+need+to+"accumulate"+the+results+of+each+comparison
++//+because++you+can+return+immediately+when+a+mismatch+is+detected.
++for+(int+i+=+0;+i+<+this.features.length;+i%2B%2B)+{
++++if+(this.features[i]+!=+x.features[i])+{
++++++return+false;
++++}
++}
++return+true;
}|2204376|entityMap^0|A|6|K|5|0|8|4|D|5|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|X|8|@$9|Y|A|Z|B|C]|$9|10|A|11|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|17|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|18|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|19|8|@]|D|@]|E|$K|L]]|$1|Q|3|-4|5|6|7|1A|8|@]|D|@]|E|$]]|$1|R|3|S|5|6|7|1B|8|@]|D|@]|E|$]]|$1|T|3|U|5|J|7|1C|8|@]|D|@]|E|$K|L]]|$1|V|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|W|$]]

The bug in the initial code was initializing <code>result</code> to <code>false</code>. That caused the loop to exit immediately, before the first comparison.

Note that it's considered a less-than-best practice to compare boolean values to <code>true</code> and <code>false</code>. At best, it's redundant. At worst, you're likely to create an error that's hard to spot:

<pre><code>if (some_value = false) { // DON'T do this -- it's always false!
</code></pre>

I've suggested before that, if you absolutely must do this, perhaps due to an undiagnosed psychological condition or a tech lead who should really have been in management, protect yourself by using Yoda conditions:

<pre><code>if (false == some_value) { // Syntax error, a single "=" will create.
</code></pre>

<hr>

Here's a corrected and optimized version of the original code:

<pre><code>public boolean equals (FeatureVector x) {

 // Do the "cheapest" test first, so you have an opportunity to return
 // without waiting for the loop to run.
 if (this.features.length != x.features.length) {
 return false;
 }

 // There's no need to "accumulate" the results of each comparison
 // because you can return immediately when a mismatch is detected.
 for (int i = 0; i &lt; this.features.length; i++) {
 if (this.features[i] != x.features[i]) {
 return false;
 }
 }
 return true;
}
</code></pre>

blocks|key|2150721|text|你的逻辑中有一些地方可能会出错。我会重写它，并在我进行的过程中进行评论。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2150722|public+boolean+equals+(FeatureVector+x+)
{

++++/*
+++++*+Check+for+the+length+first,+if+the+lengths+don't+match+then
+++++*+you+don't+have+to+bother+checking+each+elements.+Saves+time!
+++++*/
++++if+(this.features.length+!=+x.features.length)+return+false;

++++for+(int+i+=0+;+i+<+this.features.length;+i%2B%2B)+{
++++++++/*
+++++++++*+As+soon+as+you+find+a+mismatching+element,+return+out+of+the
+++++++++*+loop+and+method,+no+need+to+keep+checking.+Saves+time!
+++++++++*/
++++++++if+(this.features[i]+!=+x.features[i])+return+false;
++++}

++++//+If+the+logic+makes+it+this+far,+then+all+elements+are+equal
++++return+true;
}|code-block|syntax|javascript|2150723|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|$]]

There are a few things that could go wrong with your logic. I'll rewrite it and comment as I go along.

<pre><code>public boolean equals (FeatureVector x )
{

 /*
 * Check for the length first, if the lengths don't match then
 * you don't have to bother checking each elements. Saves time!
 */
 if (this.features.length != x.features.length) return false;

 for (int i =0 ; i &lt; this.features.length; i++) {
 /*
 * As soon as you find a mismatching element, return out of the
 * loop and method, no need to keep checking. Saves time!
 */
 if (this.features[i] != x.features[i]) return false;
 }

 // If the logic makes it this far, then all elements are equal
 return true;
}
</code></pre>

I am a new Java programmer , im trying to implement a method to check the equality between two "features" array inside my object "FeatureVector"
seems really basic but the method is not working for some reason ; it doesnt produce logical results ,and i cant seem to find a solution, please help 

<pre><code>public boolean equals (FeatureVector x )
{
 boolean result =false ; 
 boolean size = false ;
 for (int i =0 ; (i &lt; this.features.length &amp;&amp; result == true );i ++ )
 {
 if (this.features[i] == x.features[i] ) {result = true ;}
 else {result = false ; }
 }

 if (this.features.length == x.features.length ) {size = true ;}
 else {size =false; }
 return (result &amp;&amp; size) ; 
}
</code></pre>

Equals method not working

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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我是一个新的Java程序员，我正在尝试实现一个方法来检查我的对象"FeatureVector“中的两个”特征“数组之间的相等性。这个方法看起来非常基本，但是由于某些原因，这个方法不能工作；它不能产生逻辑结果，而且我似乎找不到解决方案，请帮助。public boolean equals (FeatureVector x ...

问Equals方法不起作用
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