blocks|key|1552488|text|您不能直接迭代它们，但您可以找到所有键，然后对它们进行排序。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1552489|var+a+=+new+Array();
a['b']+=+1;
a['z']+=+1;
a['a']+=+1;++++

function+keys(obj)
{
++++var+keys+=+[];

++++for(var+key+in+obj)
++++{
++++++++if(obj.hasOwnProperty(key))
++++++++{
++++++++++++keys.push(key);
++++++++}
++++}

++++return+keys;
}

keys(a).sort();+//+["a",+"b",+"z"]|code-block|syntax|javascript|1552490|然而，没有必要使变量'a‘成为数组。您实际上只是将其用作对象，并且应该像这样创建它：|1552491|var+a+=+{};
a["key"]+=+"value";|1552492|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<p>You cannot iterate over them directly, but you can find all the keys and then just sort them.</p>

<pre><code>var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;    

function keys(obj)
{
    var keys = [];

    for(var key in obj)
    {
        if(obj.hasOwnProperty(key))
        {
            keys.push(key);
        }
    }

    return keys;
}

keys(a).sort(); // ["a", "b", "z"]
</code></pre>

<p>However there is no need to make the variable 'a' an array.  You are really just using it as an object and should create it like this:</p>

<pre><code>var a = {};
a["key"] = "value";
</code></pre>


blocks|key|1337054|text|您可以使用Object.keys内置方法：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1337055|var+sorted_keys+=+Object.keys(a).sort()|code-block|syntax|javascript|1337056|(注意:这不适用于不支持EcmaScript5的非常旧的浏览器，特别是IE6、7和8。有关详细的最新统计信息，请参阅this+table)|1337057|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Object/keys|1|http://caniuse.com/#search=es5^0|5|B|0|0|0|1M|A|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|F|7|Y|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|Z|8|@]|9|@$A|10|B|11|1|12]]|C|$]]|$1|K|3|-4|5|6|7|13|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]|S|$5|N|O|P|C|$Q|T]]]]

<p>You can use the <a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Object/keys" rel="noreferrer">Object.keys</a> built-in method:</p>

<pre><code>var sorted_keys = Object.keys(a).sort()
</code></pre>

<p>(Note: this does not work in very old browsers not supporting EcmaScript5, notably IE6, 7 and 8. For detailed up-to-date statistics, see <a href="http://caniuse.com/#search=es5" rel="noreferrer">this table</a>)</p>


blocks|key|1336930|text|您甚至可以将其原型化为object：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1336931|Object.prototype.iterateSorted+=+function(worker)
{
++++var+keys+=+[];
++++for+(var+key+in+this)
++++{
++++++++if+(this.hasOwnProperty(key))
++++++++++++keys.push(key);
++++}
++++keys.sort();

++++for+(var+i+=+0;+i+<+keys.length;+i%2B%2B)
++++{
++++++++worker(this[+keys[i]+]);
++++}
}|code-block|syntax|javascript|1336932|和用法：|1336933|var+myObj+=+{+a:1,+b:2+};
myObj.iterateSorted(function(value)
{
++++alert(value);
}+|1336934|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<p>you could even prototype it onto object:</p>

<pre><code>Object.prototype.iterateSorted = function(worker)
{
    var keys = [];
    for (var key in this)
    {
        if (this.hasOwnProperty(key))
            keys.push(key);
    }
    keys.sort();

    for (var i = 0; i &lt; keys.length; i++)
    {
        worker(this[ keys[i] ]);
    }
}
</code></pre>

<p>and the usage:</p>

<pre><code>var myObj = { a:1, b:2 };
myObj.iterateSorted(function(value)
{
    alert(value);
} 
</code></pre>


blocks|key|1337022|text|我同意Swingley's+answer的观点，我认为这是一个重要的观点，许多这些更复杂的解决方案都缺失了。如果您只关心关联数组中的键，并且所有值都是“1”，那么只需将“键”作为值存储在数组中。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1337023|而不是：|1337024|var+a+=+{+b:1,+z:1,+a:1+};
//+relatively+elaborate+code+to+retrieve+the+keys+and+sort+them|code-block|syntax|javascript|1337025|使用：|1337026|var+a+=+[+'b',+'z',+'a'+];
alert(a.sort());|1337027|这样做的一个缺点是，您无法确定是否可以轻松地设置特定的密钥。有关该问题的答案，请参阅this+answer+to+javascript+function+inArray。提出的解决方案的一个问题是，a.hasValue('key')将比a['key']稍微慢一些。这在您的代码中可能重要，也可能无关紧要。|style|CODE|1337028|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/890807/iterate-over-a-javascript-associative-array-in-sorted-order/891017#891017|1|https://stackoverflow.com/questions/890782/javascript-function-inarray/890798#890798|2|https://stackoverflow.com/questions/890782^0|3|H|0|0|0|0|0|0|2R|H|3A|8|16|B|1|1L|R|2|0^^$0|@$1|2|3|4|5|6|7|14|8|@]|9|@$A|15|B|16|1|17]]|C|$]]|$1|D|3|E|5|6|7|18|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|19|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|1A|8|@]|9|@]|C|$]]|$1|M|3|N|5|H|7|1B|8|@]|9|@]|C|$I|J]]|$1|O|3|P|5|6|7|1C|8|@$A|1D|B|1E|Q|R]|$A|1F|B|1G|Q|R]]|9|@$A|1H|B|1I|1|1J]|$A|1K|B|1L|1|1M]]|C|$]]|$1|S|3|-4|5|6|7|1N|8|@]|9|@]|C|$]]]|T|$U|$5|V|W|X|C|$Y|Z]]|10|$5|V|W|X|C|$Y|11]]|12|$5|V|W|X|C|$Y|13]]]]

<p>I agree with <a href="https://stackoverflow.com/questions/890807/iterate-over-a-javascript-associative-array-in-sorted-order/891017#891017">Swingley's answer</a>, and I think it is an important point a lot of these more elaborate solutions are missing. If you are only concerned with the keys in the associative array and all the values are '1', then simply store the 'keys' as values in an array.</p>

<p>Instead of:</p>

<pre><code>var a = { b:1, z:1, a:1 };
// relatively elaborate code to retrieve the keys and sort them
</code></pre>

<p>Use:</p>

<pre><code>var a = [ 'b', 'z', 'a' ];
alert(a.sort());
</code></pre>

<p>The one drawback to this is that you can not determine whether a specific key is set as easily. See <a href="https://stackoverflow.com/questions/890782/javascript-function-inarray/890798#890798">this answer</a> to <a href="https://stackoverflow.com/questions/890782">javascript function inArray</a> for an answer to that problem. One issue with the solution presented is that <code>a.hasValue('key')</code> is going to be slightly slower than <code>a['key']</code>. That may or may not matter in your code.</p>


blocks|key|1336976|text|没有简洁的方法来直接操作Javascript对象的“键”。它实际上并不是为此而设计的。您是否可以自由地将数据放入比常规对象(或示例代码所建议的数组)更好的内容中？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1336977|如果是这样的话，如果您的问题可以重新表述为“如果我想按排序的顺序迭代键，我应该使用哪个类字典对象？”然后，您可以开发一个如下所示的对象：|1336978|var+a+=+{
++keys+:+new+Array(),
++hash+:+new+Object(),
++set+:+function(key,+value)+{
++++if+(typeof(this.hash[key])+==+"undefined")+{+this.keys.push(key);+}
++++this.hash[key]+=+value;
++},
++get+:+function(key)+{
++++return+this.hash[key];
++},
++getSortedKeys+:+function()+{
++++this.keys.sort();
++++return+this.keys;
++}
};

//+sample+use
a.set('b',1);
a.set('z',1);
a.set('a',1);
var+sortedKeys+=+a.getSortedKeys();
for+(var+i+in+sortedKeys)+{+print(sortedKeys[i]);+}|code-block|syntax|javascript|1336979|如果您无法控制数据在常规对象中的事实，此实用程序会将常规对象转换为您的全功能字典：|1336980|a.importObject+=+function(object)+{
++for+(var+i+in+object)+{+this.set(i,+object);+}
};|1336981|为了简单起见，这是一个对象定义(而不是一个可重用的构造函数)；可以随意编辑。|1336982|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|T|8|@]|9|@]|A|$]]|$1|K|3|L|5|F|7|U|8|@]|9|@]|A|$G|H]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<p>There's no concise way to directly manipulate the "keys" of a Javascript object. It's not really designed for that. Do you have the freedom to put your data in something better than a regular object (or an Array, as your sample code suggests)?</p>

<p>If so, and if your question could be rephrased as "What dictionary-like object should I use if I want to iterate over the keys in sorted order?" then you might develop an object like this:</p>

<pre><code>var a = {
  keys : new Array(),
  hash : new Object(),
  set : function(key, value) {
    if (typeof(this.hash[key]) == "undefined") { this.keys.push(key); }
    this.hash[key] = value;
  },
  get : function(key) {
    return this.hash[key];
  },
  getSortedKeys : function() {
    this.keys.sort();
    return this.keys;
  }
};

// sample use
a.set('b',1);
a.set('z',1);
a.set('a',1);
var sortedKeys = a.getSortedKeys();
for (var i in sortedKeys) { print(sortedKeys[i]); }
</code></pre>

<p>If you have no control over the fact that the data is in a regular object, this utility would convert the regular object to your fully-functional dictionary:</p>

<pre><code>a.importObject = function(object) {
  for (var i in object) { this.set(i, object); }
};
</code></pre>

<p>This was a object definition (instead of a reusable constructor function) for simplicity; edit at will.</p>


blocks|key|1336857|text|在第一个for循环中获取键，对其进行排序，然后在第二个for循环中使用排序后的结果。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1336858|var+a+=+new+Array();
a['b']+=+1;
a['z']+=+1;
a['a']+=+1;

var+b+=+[];
for+(k+in+a)+b.push(k);
b.sort();
for+(var+i+=+0;+i+<+b.length;+%2B%2Bi)+alert(b[i]);|code-block|syntax|javascript|1336859|entityMap^0|4|3|R|3|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

<p>Get the keys in the first <code>for</code> loop, sort it, use the sorted result in the 2nd <code>for</code> loop.</p>

<pre><code>var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;

var b = [];
for (k in a) b.push(k);
b.sort();
for (var i = 0; i &lt; b.length; ++i) alert(b[i]);
</code></pre>


blocks|key|1337097|text|您可以使用underscore.js库中的keys函数获取键，然后使用sort()数组方法对其进行排序：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1337098|var+sortedKeys+=+_.keys(dict).sort();|code-block|syntax|javascript|1337099|下划线源代码中的keys函数：|1337100|//+Retrieve+the+names+of+an+object's+properties.
//+Delegates+to+**ECMAScript+5**'s+native+`Object.keys`
_.keys+=+nativeKeys+%7C%7C+function(obj)+{
++++if+(obj+!==+Object(obj))+throw+new+TypeError('Invalid+object');
++++var+keys+=+[];
++++for+(var+key+in+obj)+if+(_.has(obj,+key))+keys.push(key);
++++return+keys;
};++++

//+Shortcut+function+for+checking+if+an+object+has+a+given+property+directly
//+on+itself+(in+other+words,+not+on+a+prototype).
_.has+=+function(obj,+key)+{
++++return+hasOwnProperty.call(obj,+key);
};|1337101|entityMap|0|LINK|mutability|MUTABLE|url|http://underscorejs.org/|1|http://underscorejs.org/#keys^0|L|4|Z|6|5|D|0|L|4|1|0|0|8|4|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]]|D|@$9|13|A|14|1|15]|$9|16|A|17|1|18]]|E|$]]|$1|F|3|G|5|H|7|19|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|1A|8|@$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|1D|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|1E|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]|W|$5|R|S|T|E|$U|X]]]]

<p>You can use the <a href="http://underscorejs.org/#keys" rel="nofollow"><code>keys</code></a> function from the <a href="http://underscorejs.org/" rel="nofollow">underscore.js</a> library to get the keys, then the <code>sort()</code> array method to sort them:</p>

<pre><code>var sortedKeys = _.keys(dict).sort();
</code></pre>

<p>The <code>keys</code> function in the underscore's source code:</p>

<pre><code>// Retrieve the names of an object's properties.
// Delegates to **ECMAScript 5**'s native `Object.keys`
_.keys = nativeKeys || function(obj) {
    if (obj !== Object(obj)) throw new TypeError('Invalid object');
    var keys = [];
    for (var key in obj) if (_.has(obj, key)) keys.push(key);
    return keys;
};    

// Shortcut function for checking if an object has a given property directly
// on itself (in other words, not on a prototype).
_.has = function(obj, key) {
    return hasOwnProperty.call(obj, key);
};
</code></pre>


blocks|key|1336993|text|<script+type="text/javascript">
++++var+a+=+{
++++++++b:1,
++++++++z:1,
++++++++a:1
++++};+//+your+JS+Object
++++var+keys+=+[];
++++for+(key+in+a)+{
++++++++keys.push(key);
++++}
++++keys.sort();
++++var+i+=+0;
++++var+keyslen+=+keys.length;
++++var+str+=+'';
++++//SORTED+KEY+ITERATION
++++while+(i+<+keyslen)+{
++++++++str+%2B=+keys[i]+%2B+'=>'+%2B+a[keys[i]]+%2B+'\n';
++++++++%2B%2Bi;
++++}
++++alert(str);
++++/*RESULT:
++++a=>1
++++b=>1
++++z=>1
++++*/
</script>|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1336994|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>&lt;script type="text/javascript"&gt;
    var a = {
        b:1,
        z:1,
        a:1
    }; // your JS Object
    var keys = [];
    for (key in a) {
        keys.push(key);
    }
    keys.sort();
    var i = 0;
    var keyslen = keys.length;
    var str = '';
    //SORTED KEY ITERATION
    while (i &lt; keyslen) {
        str += keys[i] + '=&gt;' + a[keys[i]] + '\n';
        ++i;
    }
    alert(str);
    /*RESULT:
    a=&gt;1
    b=&gt;1
    z=&gt;1
    */
&lt;/script&gt;
</code></pre>


blocks|key|1552693|text|​|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1552694|var+a+=+new+Array();
a['b']+=+1;
a['z']+=+1;
a['a']+=+1;


var+keys=Object.keys(a).sort();
for(var+i=0,key=keys[0];i<keys.length;key=keys[%2B%2Bi]){
++document.write(key%2B'+:+'%2Ba[key]%2B'<br>');
}|code-block|syntax|javascript|1552695|1552696|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>var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;


var keys=Object.keys(a).sort();
for(var i=0,key=keys[0];i&lt;keys.length;key=keys[++i]){
  document.write(key+' : '+a[key]+'&lt;br&gt;');
}</code></pre>
</div>
</div>
</p>


blocks|key|1552740|text|我真的很喜欢@luke-schafer的原型想法，但也听到了他对原型问题的看法。使用一个简单的函数怎么样？|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1552741|​|1552742|function+sortKeysAndDo(+obj,+worker+)+{
++var+keys+=+Object.keys(obj);
++keys.sort();
++for+(var+i+=+0;+i+<+keys.length;+i%2B%2B)+{
+++++worker(keys[i],+obj[keys[i]]);
++}
}

function+show(+key,+value+)+{
++document.write(+key+%2B+'+:+'+%2B+value+%2B'<br>'+);
}

var+a+=+new+Array();
a['b']+=+1;
a['z']+=+1;
a['a']+=+1;

sortKeysAndDo(+a,+show);

var+my_object+=+{+'c':+3,+'a':+1,+'b':+2+};

sortKeysAndDo(+my_object,+show);|code-block|syntax|javascript|1552743|1552744|这似乎消除了原型的问题，并仍然为对象提供了排序迭代器。不过，我并不是一个真正的JavaScript专家，所以我很想知道这个解决方案是否有我遗漏的隐藏缺陷。|1552745|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|P|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|Q|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|R|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|M|$]]

<p>I really like @luke-schafer's prototype idea, but also hear what he is saying about the issues with prototypes. What about using a simple function? </p>

<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 sortKeysAndDo( obj, worker ) {
  var keys = Object.keys(obj);
  keys.sort();
  for (var i = 0; i &lt; keys.length; i++) {
     worker(keys[i], obj[keys[i]]);
  }
}

function show( key, value ) {
  document.write( key + ' : ' + value +'&lt;br&gt;' );
}

var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;

sortKeysAndDo( a, show);

var my_object = { 'c': 3, 'a': 1, 'b': 2 };

sortKeysAndDo( my_object, show);</code></pre>
</div>
</div>
</p>

<p>This seems to eliminate the issues with prototypes and still provide a sorted iterator for objects. I am not really a JavaScript guru, though, so I'd love to know if this solution has hidden flaws I missed.</p>


<p>Let's say I have a Javascript associative array (a.k.a. hash, a.k.a. dictionary):</p>

<pre><code>var a = new Array();
a['b'] = 1;
a['z'] = 1;
a['a'] = 1;
</code></pre>

<p>How can I iterate over the keys in sorted order? If it helps simplify things, I don't even need the values (they're all just the number 1).</p>


Iterate over a Javascript associative array in sorted order

假设我有一个Javascript关联数组(也称为。哈希，也就是。字典)：var a = new Array();a['b'] = 1;a['z'] = 1;a['a'] = 1;如何按排序顺序遍历键？如果它有助于简化事情，我甚至不需要这些值(它们都只是数字1)。

问按排序顺序遍历Javascript关联数组
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