blocks|key|805586|text|就这样做吧：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|805587|var+myVar+=+{
+++++"9":"Automotive+&+Industrial",
+++++"1":"Books",
+++++"7":"Clothing"
};

//+if+you+want+to+add+a+property,+then...

myVar["5"]="Electronics";+//+note+that+it+won't+be+"first"+or+"last",+it's+just+"5"|code-block|syntax|javascript|805588|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|$]]

Just do it this way:

<pre><code>var myVar = {
 "9":"Automotive &amp; Industrial",
 "1":"Books",
 "7":"Clothing"
};

// if you want to add a property, then...

myVar["5"]="Electronics"; // note that it won't be "first" or "last", it's just "5"
</code></pre>

blocks|key|634729|text|根据定义，Javascript对象没有与它们关联的顺序，因此这是不可能的。|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|634730|如果需要订单，则应该使用对象的数组：|634731|var+myArray+=+[
++++{number:+'9',+value:'Automotive+&+Industrial'},
++++{number:+'1',+value:'Books'},
++++{number:+'7',+value:'Clothing'}
]|code-block|syntax|javascript|634732|然后，如果要在第一个位置插入某些内容，可以使用数组的unshift方法。|634733|myArray.unshift({number:'5',+value:'Electronics'})

//myArray+is+now+the+following
[{number:'5',+value:'Electronics'},
+{number:+'9',+value:'Automotive+&+Industrial'},
+{number:+'1',+value:'Books'},
+{number:+'7',+value:'Clothing'}]|634734|这里有更多的细节：JavaScript保证对象属性顺序吗？|634735|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/q/5525795/339967^0|5|V|0|F|2|0|0|0|0|9|K|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|16|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|17|8|@]|D|@]|E|$]]|$1|O|3|P|5|J|7|18|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|19|8|@]|D|@$9|1A|A|1B|1|1C]]|E|$]]|$1|S|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]]]

Javascript objects don't have an order associated with them by definition, so this is impossible. 

You should use an array of objects if you need an order:

<pre><code>var myArray = [
 {number: '9', value:'Automotive &amp; Industrial'},
 {number: '1', value:'Books'},
 {number: '7', value:'Clothing'}
]
</code></pre>

then if you want to insert something in the first position, you can use the unshift method of Arrays.

<pre><code>myArray.unshift({number:'5', value:'Electronics'})

//myArray is now the following
[{number:'5', value:'Electronics'},
 {number: '9', value:'Automotive &amp; Industrial'},
 {number: '1', value:'Books'},
 {number: '7', value:'Clothing'}]
</code></pre>

more detail here:
<a href="https://stackoverflow.com/q/5525795/339967">Does JavaScript Guarantee Object Property Order?</a>

blocks|key|634690|text|无法向JSON添加新条目并控制它们的位置。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|634691|如果您想处理order奇怪，因为对象是无序的，那么基本上必须创建一个新对象并追加数据。|634692|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

There is no way to add new entries to JSON and control the position of them. 

If you want to deal with order [strange since objects are unordered], you would have to basically create a new object and append the data.

blocks|key|805558|text|Javascript对象属性没有确定的排序。无论属性的顺序如何，都可以访问它们。如果您依赖于它们在for-in循环中的特定顺序，我建议重新考虑您的策略。不同的浏览器将采用不同的方法对属性进行排序。虽然许多浏览器实际上会按照创建它们的顺序来处理它们，但是这种行为实际上并没有在语言规范中定义，所以您不能依赖它。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|805559|entityMap^0|1D|6|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

Javascript object properties are not deterministically ordered. Properties are accessible no matter what order they're in. If you are depending on them to be in a specific order for a <code>for-in</code> loop, I would suggest rethinking your strategy. Different browsers will take different approaches to ordering the properties. While many browsers will in fact process them in the order you created them, that behavior isn't actually defined in the language spec so you cannot rely on it.

blocks|key|1285611|text|我认为不转移的问题可能是因为你是一个关联数组.关联数组的定义|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1285612|这可能是一次黑客攻击，但如果您必须在JSON对象的开头具有该值，那么不如：|1285613|var+myNewVar={'5':'Electronics'};
for+(xx+in+myVar)+{
++++myNewVar[xx]=myVar[xx];
}|code-block|syntax|javascript|1285614|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Associative_array^0|N|7|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@$A|T|B|U|1|V]]|C|$]]|$1|D|3|E|5|6|7|W|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|X|8|@]|9|@]|C|$I|J]]|$1|K|3|-4|5|6|7|Y|8|@]|9|@]|C|$]]]|L|$M|$5|N|O|P|C|$Q|R]]]]

I think the unshift issue might come from the fact that you an associative array.
<a href="http://en.wikipedia.org/wiki/Associative_array" rel="nofollow">Definition of associative array</a>

This might be a hack but if you MUST have that value at the start of the JSON object, how about:

<pre><code>var myNewVar={'5':'Electronics'};
for (xx in myVar) {
 myNewVar[xx]=myVar[xx];
}
</code></pre>

blocks|key|633138|text|这可以使用房客合并函数来完成，如下所示：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|633139|var+myObj+=+_.merge({+col1:+'col+1',+col2:+'col+2'},+{+col3:+'col+3',+col4:+'col+4'+});|code-block|syntax|javascript|633140|您的最终对象将如下所示：|633141|{+col1:+'col+1',+col2:+'col+2',+col3:+'col+3',+col4:+'col+4'+}|633142|正如其他人所提到的，不能保证对象中的键顺序将保持不变，这取决于您如何处理它。但是，如果您执行合并作为您的最后一步，您应该是好的。注意，“merge”函数将产生一个全新的对象，它不会改变传递给它的任何一个对象。|633143|entityMap|0|LINK|mutability|MUTABLE|url|http://lodash.com/docs#merge^0|5|2|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@$A|X|B|Y|1|Z]]|C|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|C|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@]|C|$]]|$1|K|3|L|5|F|7|12|8|@]|9|@]|C|$G|H]]|$1|M|3|N|5|6|7|13|8|@]|9|@]|C|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|C|$]]]|P|$Q|$5|R|S|T|C|$U|V]]]]

This Can be done using the <a href="http://lodash.com/docs#merge" rel="nofollow">lodash</a> merge function like so:

<pre><code>var myObj = _.merge({ col1: 'col 1', col2: 'col 2'}, { col3: 'col 3', col4: 'col 4' });
</code></pre>

Your final object will look like this:

<pre><code>{ col1: 'col 1', col2: 'col 2', col3: 'col 3', col4: 'col 4' }
</code></pre>

As others mentioned, there is no guarantee that the order of the keys in the object will remain the same, depending on what you do with it. But, if you perform the merge as your final step, you should be ok. Note, the 'merge' function will produce a completely new object, it will not alter either of the objects you pass into it.

blocks|key|1285620|text|试着做这样的事：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1285621|myObject.sort(function(a,b)+{+return+parseFloat(a.price)+-+parseFloat(b.price)+}+);|code-block|syntax|javascript|1285622|或|1285623|myObject.sort(function(a,b)+{+return+parseFloat(a.get("price"))+-+parseFloat(b.get("price"))+}+);|1285624|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|$]]

Try something like that:

<pre><code>myObject.sort(function(a,b) { return parseFloat(a.price) - parseFloat(b.price) } );
</code></pre>

or

<pre><code>myObject.sort(function(a,b) { return parseFloat(a.get("price")) - parseFloat(b.get("price")) } );
</code></pre>

blocks|key|633145|text|字符串化和修改|type|unstyled|depth|inlineStyleRanges|entityRanges|data|633146|var+foo+=+{a:1,b:2,c:3};
var+bar+=+JSON.stringify(foo);
foo+=+JSON.parse('{"d":4,'+%2B+bar.slice(1));
alert(JSON.stringify(foo));|code-block|syntax|javascript|633147|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|$]]

stringify and modify
<pre><code>var foo = {a:1,b:2,c:3};
var bar = JSON.stringify(foo);
foo = JSON.parse('{&quot;d&quot;:4,' + bar.slice(1));
alert(JSON.stringify(foo));
</code></pre>

I have this JSON:

<pre><code>var myVar = {
 "9":"Automotive &amp; Industrial",
 "1":"Books",
 "7":"Clothing"
};
</code></pre>

I want to add a new element at the beginning, I want to end up having this:

<blockquote>
<pre><code>var myVar = {
 "5":"Electronics",
 "9":"Automotive &amp; Industrial",
 "1":"Books",
 "7":"Clothing"
};
</code></pre>
</blockquote>

I tried this but it is not working:

<pre><code>myVar.unshift({"5":"Electronics"});
</code></pre>

Thanks!

Add a new property at the beginning of a JSON object

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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我有一个JSON：var myVar = {     "9":"Automotive & Industrial",     "1":"Books",     "7":"Clothing"};我想在开始时添加一个新元素，我希望最终得到这样的结果：var myVar ={“5”：“电子”，“9”：“汽车和工业”，“1”：“书籍”，“7”：“服装”}；我试过了，但没有用：myVar.unshift({"

问在JSON对象的开头添加一个新属性
EN

回答 8

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问在JSON对象的开头添加一个新属性EN

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问在JSON对象的开头添加一个新属性
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