blocks|key|972942|text|function+hasDuplicates(){+if+(duplicate+=+true)+{+return+true+}+}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|972943|这句话|unstyled|972944|duplicate+=+true|972945|意思是“给变量duplicate赋值true并返回true。这不是你想要的。|offset|length|style|CODE|972946|entityMap^0|0|0|0|7|9|I|4|P|4|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|R|8|@]|9|@]|A|$]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$B|C]]|$1|I|3|J|5|F|7|T|8|@$K|U|L|V|M|N]|$K|W|L|X|M|N]|$K|Y|L|Z|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|F|7|10|8|@]|9|@]|A|$]]]|P|$]]

<pre><code>function hasDuplicates(){ if (duplicate = true) { return true } }
</code></pre>

<p>The statement</p>

<pre><code>duplicate = true
</code></pre>

<p>means "assign the variable <code>duplicate</code> the value <code>true</code> and return <code>true</code>.  That's not what you want.</p>


blocks|key|972952|text|function+hasDuplicates()+{
++return+duplicate+?+'true'+:+'false';
}

var+numbers=+[14,+50,+27,+52,++41,+5,+9,+25,+10,+6];
var+unique+=+{};
numbers.forEach(+n+=>+{+unique[n]+=+1;+}+);
var+duplicate+=+numbers.length+!=+unique.length;|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|972953|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>function hasDuplicates() {
  return duplicate ? 'true' : 'false';
}

var numbers= [14, 50, 27, 52,  41, 5, 9, 25, 10, 6];
var unique = {};
numbers.forEach( n =&gt; { unique[n] = 1; } );
var duplicate = numbers.length != unique.length;
</code></pre>


blocks|key|1005041|text|我试过你的代码，如果没有重复，我会得到一个空数组，所以我会重写hasDuplicates函数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005042|function+hasDuplicates(){
++return+duplicate.length+===+0
}|code-block|syntax|javascript|1005043|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|$]]

<p>I tried your code and I get an empty array if there's no duplicate
so I would rewrite hasDuplicates function to this</p>

<pre><code>function hasDuplicates(){
  return duplicate.length === 0
}
</code></pre>


blocks|key|972948|text|使用Array.from(新集合(数组))创建唯一数组，然后比较两个数组的长度。如果唯一数组的元素较少，则是重复的情况！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|972949|var+numbers=+[14,+50,+27,+52,++41,+5,+9,+25,+10,+6];
//console.log(numbers);
var+uniqueArrays+=+Array.from(new+Set(numbers));
if+(uniqueArrays.length+<+numbers.length)
++++console.log('Has+duplicate!');
else
++++console.log('No+duplicate!');|code-block|syntax|javascript|972950|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|$]]

<p>Use Array.from(new Set(array)) to create unique array, then compare length of two array. If unique array has less element, it's the case of duplicate!</p>

<pre><code>var numbers= [14, 50, 27, 52,  41, 5, 9, 25, 10, 6];
//console.log(numbers);
var uniqueArrays = Array.from(new Set(numbers));
if (uniqueArrays.length &lt; numbers.length)
    console.log('Has duplicate!');
else
    console.log('No duplicate!');
</code></pre>


blocks|key|1005045|text|您可以使用Array#some、Array#every或Array#filter来简化这一过程。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1005046|JS+Perf|1005047|如果您不关心实际的重复值|1005048|使用Array#some|1005049|​|1005050|const+numbers+=+[14,+50,+27,+52,+25,+41,+5,+9,+25,+10,+25,+6];

const+hasDuplicates+=+numbers.some((number,+index,+a)+=>+numbers.indexOf(number)+!==+index);

console.log(hasDuplicates);|code-block|syntax|javascript|1005051|1005052|使用Array#every|1005053|1005054|var+numbers+=+[14,+50,+27,+52,+25,+41,+5,+9,+25,+10,+25,+6];

var+hasDuplicates+=+!numbers.every((number,+index)+=>+numbers.indexOf(number)+===+index);

console.log(hasDuplicates);|1005055|1005056|使用Array#filter|1005057|const+numbers+=+[14,+50,+27,+52,+25,+41,+5,+9,+25,+10,+25,+6];
const+uniques+=+numbers.filter((number,+index)+=>+numbers.indexOf(number)+===+index);
const+hasDuplicates+=+numbers.length+!==+uniques.length;

console.log(uniques,+hasDuplicates);|1005058|1005059|如果你真的在乎|1005060|1005061|const+numbers+=+[14,+50,+27,+52,+25,+41,+5,+9,+25,+10,+25,+6];

const+duplicates+=+[];

const+uniques+=+numbers.filter((number,+index)+=>+{
++return+numbers.indexOf(number)+===+index+%7C%7C+!duplicates.includes(number)+&&+duplicates.push(number)+&&+false;
});

function+hasDuplicates(){
++return+!!duplicates.length;
}

console.log(duplicates,+uniques,+hasDuplicates());|1005062|1005063|entityMap|0|LINK|mutability|MUTABLE|url|https://jsperf.com/array-filter-vs-some-vs-every-vs-set^0|5|A|G|B|S|C|0|0|7|0|0|0|2|A|0|0|0|0|2|B|0|0|0|0|2|C|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1I|8|@$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1P|8|@]|D|@$9|1Q|A|1R|1|1S]]|E|$]]|$1|H|3|I|5|6|7|1T|8|@]|D|@]|E|$]]|$1|J|3|K|5|6|7|1U|8|@$9|1V|A|1W|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|1X|8|@]|D|@]|E|$]]|$1|N|3|O|5|P|7|1Y|8|@]|D|@]|E|$Q|R]]|$1|S|3|M|5|6|7|1Z|8|@]|D|@]|E|$]]|$1|T|3|U|5|6|7|20|8|@$9|21|A|22|B|C]]|D|@]|E|$]]|$1|V|3|M|5|6|7|23|8|@]|D|@]|E|$]]|$1|W|3|X|5|P|7|24|8|@]|D|@]|E|$Q|R]]|$1|Y|3|M|5|6|7|25|8|@]|D|@]|E|$]]|$1|Z|3|10|5|6|7|26|8|@$9|27|A|28|B|C]]|D|@]|E|$]]|$1|11|3|12|5|P|7|29|8|@]|D|@]|E|$Q|R]]|$1|13|3|M|5|6|7|2A|8|@]|D|@]|E|$]]|$1|14|3|15|5|6|7|2B|8|@]|D|@]|E|$]]|$1|16|3|M|5|6|7|2C|8|@]|D|@]|E|$]]|$1|17|3|18|5|P|7|2D|8|@]|D|@]|E|$Q|R]]|$1|19|3|M|5|6|7|2E|8|@]|D|@]|E|$]]|$1|1A|3|-4|5|6|7|2F|8|@]|D|@]|E|$]]]|1B|$1C|$5|1D|1E|1F|E|$1G|1H]]]]

<p>You could simplify this by using  <code>Array#some</code>,  <code>Array#every</code> or <code>Array#filter</code>.</p>

<p><a href="https://jsperf.com/array-filter-vs-some-vs-every-vs-set" rel="nofollow noreferrer">JS Perf</a></p>

<p>If you don't care about the actual duplicate values</p>

<p>Using <code>Array#some</code></p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>const numbers = [14, 50, 27, 52, 25, 41, 5, 9, 25, 10, 25, 6];

const hasDuplicates = numbers.some((number, index, a) =&gt; numbers.indexOf(number) !== index);

console.log(hasDuplicates);</code></pre>
</div>
</div>
</p>

<p>Using <code>Array#every</code></p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>var numbers = [14, 50, 27, 52, 25, 41, 5, 9, 25, 10, 25, 6];

var hasDuplicates = !numbers.every((number, index) =&gt; numbers.indexOf(number) === index);

console.log(hasDuplicates);</code></pre>
</div>
</div>
</p>

<p>Using <code>Array#filter</code>
<div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>const numbers = [14, 50, 27, 52, 25, 41, 5, 9, 25, 10, 25, 6];
const uniques = numbers.filter((number, index) =&gt; numbers.indexOf(number) === index);
const hasDuplicates = numbers.length !== uniques.length;

console.log(uniques, hasDuplicates);</code></pre>
</div>
</div>
</p>

<p>If you do care</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>const numbers = [14, 50, 27, 52, 25, 41, 5, 9, 25, 10, 25, 6];

const duplicates = [];

const uniques = numbers.filter((number, index) =&gt; {
  return numbers.indexOf(number) === index || !duplicates.includes(number) &amp;&amp; duplicates.push(number) &amp;&amp; false;
});

function hasDuplicates(){
  return !!duplicates.length;
}

console.log(duplicates, uniques, hasDuplicates());
    </code></pre>
</div>
</div>
</p>


<p>So I am trying to write a code where if there a duplicate numbers it returns true and if there isn't duplicates it returns false.  I get the duplicates to show up but I want it to return the word false if there aren't duplicates.  Here is the code what am I missing.</p>

<pre><code>var numbers= [14, 50, 27, 52,  41, 5, 9, 25, 10, 6];

var uniqueArray = numbers.map((number) =&gt; {
return {count:1, number: number}
})
.reduce((a, b) =&gt; {
a[b.number] = (a[b.number] || 0) + b.count
return a
}, {})

var duplicate = Object.keys(uniqueArray ).filter((a) =&gt; uniqueArray [a] &gt; 1)

//console.log(duplicate)

function hasDuplicates(){
  if (duplicate = true) {
    return true
  }
}
</code></pre>


False statement returns an empty array

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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所以我正在试着写一段代码，如果有重复的数字，则返回true，如果没有重复的数字，则返回false。我让副本出现，但是如果没有副本，我想让它返回false这个词。这是我遗漏的代码。var numbers= [14, 50, 27, 52,  41, 5, 9, 25, 10, 6];var uniqueArray = n...

问False语句返回空数组
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问False语句返回空数组
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