blocks|key|4454046|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4454047|function+getSort+(ascending)+{
++//+if+ascending,+`null`+will+be+pushed+towards+the+end+of+the+array+by+returning+1
++var+nullPosition+=+ascending+?+1+:+-1
++return+function+(a,+b)+{
++++//+if+a+is+null,+push+it+towards+whichever+end+null+elements+should+end+up
++++if+(a+==+null)+return+nullPosition
++++
++++//+Note:+at+this+point,+a+is+non-null+(previous+if+statement+handled+that+case).
++++//
++++//+If+b+is+null,+it+must+therefore+be+placed+closer+to+whichever+end+the+null
++++//+elements+should+end+up+on.+If+ascending,+null+elements+are+pulled+towards
++++//+the+right+end+of+the+array.+If+descending,+null+elements+are+pulled+towards
++++//+the+left.
++++//
++++//+Therefore,+we+return+-nullPosition.+If+ascending,+this+is+-1,+meaning+a+comes
++++//+before+b;+if+descending,+this+is+1,+meaning+a+comes+after+b.+This+is
++++//+clearly+the+correct+behavior,+since+ascending+will+push+b,+which+is+null,
++++//+towards+the+end+of+the+array+(with+-1)+and+descending+will+push+b+towards
++++//+the+beginning+of+the+array.
++++if+(b+==+null)+return+-nullPosition

++++//+OTHERWISE,+both+elements+are+non-null,+so+sort+normally.
++++//+if+a+<+b+AND
++++//+++++if+ascending,+a+comes+first,+so+return+-1+==+-nullPosition
++++//+++++if+descending,+a+comes+after,+so+return+-nullPosition+==+-(-1)+==+1
++++if+(a+<+b)+return+-nullPosition

++++//+return+the+opposite+of+the+previous+condition
++++if+(a+>+b)+return+nullPosition
++++
++++//+return+0+if+both+elements+are+equal
++++return+0
++}
}

function+write+(arr)+{+arr.forEach(function+(d)+{+document.write(d+%2B+"<br>")})}

var+toSort+=+['a',+'b',+null,+'d',+null]

var+sortA+=+getSort(true)
var+sortD+=+getSort(false)

document.write("<br>ASCENDING<br>")
write(toSort.sort(sortA))

document.write("<br>DESCENDING<br>")
write(toSort.sort(sortD))|code-block|syntax|javascript|4454048|4454049|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|K|8|@]|9|@]|A|$E|F]]|$1|G|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|M|8|@]|9|@]|A|$]]]|I|$]]

<p><div class="snippet" data-lang="js" data-hide="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function getSort (ascending) {
  // if ascending, `null` will be pushed towards the end of the array by returning 1
  var nullPosition = ascending ? 1 : -1
  return function (a, b) {
    // if a is null, push it towards whichever end null elements should end up
    if (a == null) return nullPosition
    
    // Note: at this point, a is non-null (previous if statement handled that case).
    //
    // If b is null, it must therefore be placed closer to whichever end the null
    // elements should end up on. If ascending, null elements are pulled towards
    // the right end of the array. If descending, null elements are pulled towards
    // the left.
    //
    // Therefore, we return -nullPosition. If ascending, this is -1, meaning a comes
    // before b; if descending, this is 1, meaning a comes after b. This is
    // clearly the correct behavior, since ascending will push b, which is null,
    // towards the end of the array (with -1) and descending will push b towards
    // the beginning of the array.
    if (b == null) return -nullPosition

    // OTHERWISE, both elements are non-null, so sort normally.
    // if a &lt; b AND
    //     if ascending, a comes first, so return -1 == -nullPosition
    //     if descending, a comes after, so return -nullPosition == -(-1) == 1
    if (a &lt; b) return -nullPosition

    // return the opposite of the previous condition
    if (a &gt; b) return nullPosition
    
    // return 0 if both elements are equal
    return 0
  }
}

function write (arr) { arr.forEach(function (d) { document.write(d + "&lt;br&gt;")})}

var toSort = ['a', 'b', null, 'd', null]

var sortA = getSort(true)
var sortD = getSort(false)

document.write("&lt;br&gt;ASCENDING&lt;br&gt;")
write(toSort.sort(sortA))

document.write("&lt;br&gt;DESCENDING&lt;br&gt;")
write(toSort.sort(sortD))</code></pre>
</div>
</div>
</p>


blocks|key|4454072|text|您可以使用两遍方法，首先检查null值，然后按字符串排序。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4454073|要更改排序顺序，可以交换参数或使用其中一个函数的取反结果。|4454074|​|4454075|var+data+=+['a',+'b',+null,+'d',+null];

//+ascending
data.sort(function+(a,+b)+{
++++return+(a+===+null)+-+(b+===+null)+%7C%7C+(''+%2B+a).localeCompare(b);
});
console.log(data);

//+descending
data.sort(function+(a,+b)+{
++++return+(b+===+null)+-+(a+===+null)+%7C%7C+(''+%2B+b).localeCompare(a);
});
console.log(data);|code-block|syntax|javascript|4454076|.as-console-wrapper+{+max-height:+100%25+!important;+top:+0;+}|4454077|4454078|entityMap^0|E|4|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|T|8|@$9|U|A|V|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|W|8|@]|D|@]|E|$]]|$1|H|3|I|5|6|7|X|8|@]|D|@]|E|$]]|$1|J|3|K|5|L|7|Y|8|@]|D|@]|E|$M|N]]|$1|O|3|P|5|L|7|Z|8|@]|D|@]|E|$M|N]]|$1|Q|3|I|5|6|7|10|8|@]|D|@]|E|$]]|$1|R|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|S|$]]

<p>You could use a two pass approach by checking <code>null</code> values first and then order by string.</p>

<p>To change the sort order, you could swap the parameters or use a negated result of the one of the function.</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 data = ['a', 'b', null, 'd', null];

// ascending
data.sort(function (a, b) {
    return (a === null) - (b === null) || ('' + a).localeCompare(b);
});
console.log(data);

// descending
data.sort(function (a, b) {
    return (b === null) - (a === null) || ('' + b).localeCompare(a);
});
console.log(data);</code></pre>
<pre class="snippet-code-css lang-css prettyprint-override"><code>.as-console-wrapper { max-height: 100% !important; top: 0; }</code></pre>
</div>
</div>
</p>


blocks|key|4454104|text|下面的解决方案怎么样？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4454105|var+arr+=+[null,+'e',+'a',+'b',+null,+'d',+null];

function+sortBy(arr,+ascending)+{
++++return+arr.sort((a,+b)+=>+{
++++++++if(!a)+return+ascending+?+1+:+-1;
++++++++if(!b)+return+ascending+?+-1+:+1;
++++++++if+(ascending)+return+a+>+b+?+1+:+-1;
++++++++return+a+>+b+?+-1+:+1;
++++})
}

const+ascendingArr+=+sortBy(arr,+true);
console.log(ascendingArr);
const+decendingArr+=+sortBy(arr,+false);
console.log(decendingArr);|code-block|syntax|javascript|4454106|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>What about the below solution?</p>

<pre><code>var arr = [null, 'e', 'a', 'b', null, 'd', null];

function sortBy(arr, ascending) {
    return arr.sort((a, b) =&gt; {
        if(!a) return ascending ? 1 : -1;
        if(!b) return ascending ? -1 : 1;
        if (ascending) return a &gt; b ? 1 : -1;
        return a &gt; b ? -1 : 1;
    })
}

const ascendingArr = sortBy(arr, true);
console.log(ascendingArr);
const decendingArr = sortBy(arr, false);
console.log(decendingArr);
</code></pre>


<p>There are quite a few question related to the topic, but I couldn't find the right solution for my case.</p>

<pre><code>var arr = [a, b, null, d, null]
</code></pre>

<p>and am sorting this Array with below logic</p>

<pre><code>return function(a,b){ 

    if(a === null){
      return 1;
    }
    else if(b === null){
      return -1;
    }
    else if(a === b){
      return 0;
    }
    else if(ascending) {
      return a &lt; b ? -1 : 1;
    }
    else if(!ascending) {
      return a &lt; b ? 1 : -1;
    }
  };
</code></pre>

<p>I get the following outputs for </p>

<pre><code>Ascending : [a, b,  d, null,null]

Descending : [d, b,  a, null,null]

Expected : [null, null,d, b,  a]
</code></pre>

<p>What am I doing wrong?</p>


How to sort an array with null values

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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有相当多的问题与这个主题有关，但我找不到适合我的情况的正确解决方案。var arr = [a, b, null, d, null]我用下面的逻辑对这个数组进行排序return function(a,b){     if(a === null){      return 1;    }    else if(b === ...

问如何对具有空值的数组进行排序
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