blocks|key|124347|text|对于一个对象，假设|type|unstyled|depth|inlineStyleRanges|entityRanges|data|124348|obj+=+{+a:+'a',+'1':+1+}|code-block|syntax|javascript|124349|obj.toString()给出|offset|length|style|CODE|124350|"[object+Object]"|124351|JSON.stringify(obj)给出|124352|"{"1":1,"a":"a"}"|124353|对于.toString()，当参数类型为object时，将返回默认值。另一方面，JSON.stringify返回JSON文本，可以使用JSON.parse将其转换回JSON对象|124354|entityMap|0|LINK|mutability|MUTABLE|url|http://es5.github.com/#x9.8|1|http://msdn.microsoft.com/en-us/library/ie/cc836459%2528v=vs.94%2529.aspx|2|http://msdn.microsoft.com/en-us/library/ie/cc836466%2528v=vs.94%2529.aspx^0|0|0|0|E|0|0|0|J|0|0|2|B|0|14|E|1|1V|A|2|0^^$0|@$1|2|3|4|5|6|7|16|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|17|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|18|8|@$I|19|J|1A|K|L]]|9|@]|A|$]]|$1|M|3|N|5|D|7|1B|8|@]|9|@]|A|$E|F]]|$1|O|3|P|5|6|7|1C|8|@$I|1D|J|1E|K|L]]|9|@]|A|$]]|$1|Q|3|R|5|D|7|1F|8|@]|9|@]|A|$E|F]]|$1|S|3|T|5|6|7|1G|8|@]|9|@$I|1H|J|1I|1|1J]|$I|1K|J|1L|1|1M]|$I|1N|J|1O|1|1P]]|A|$]]|$1|U|3|-4|5|6|7|1Q|8|@]|9|@]|A|$]]]|V|$W|$5|X|Y|Z|A|$10|11]]|12|$5|X|Y|Z|A|$10|13]]|14|$5|X|Y|Z|A|$10|15]]]]

for an object say

<pre><code>obj = { a: 'a', '1': 1 }
</code></pre>

<code>obj.toString()</code> gives

<pre><code>"[object Object]"
</code></pre>

<code>JSON.stringify(obj)</code> gives

<pre><code>"{"1":1,"a":"a"}"
</code></pre>

For <a href="http://es5.github.com/#x9.8">.toString()</a>, a default value is returned when the argument type is an object. <a href="http://msdn.microsoft.com/en-us/library/ie/cc836459%28v=vs.94%29.aspx">JSON.stringify</a> on the other hand returns JSON text, which can be converted back into a JSON object by using <a href="http://msdn.microsoft.com/en-us/library/ie/cc836466%28v=vs.94%29.aspx">JSON.parse</a>

blocks|key|342288|text|除非您有一个自定义对象，该对象具有返回该对象JSON.stringify的自定义.toString方法，否则不存在提供obj.toString()+==+JSON.stringify(obj)的obj。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|342289|当obj是像[1,2,3]这样的数组时，.toString()提供：|342290|"1,2,3"|code-block|syntax|javascript|342291|和JSON.stringify|342292|"[1,2,3]"|342293|它们很接近，但并不完全相同，JSON序列化的JSON没有逗号的歧义，直接作为Javascript运行，或者可以解析为JSON。|342294|请参见：|342295|["1,",2,3].toString();
//"1,,2,3"+...+so+you+can't+just+split+by+comma+and+get+original+array
//it+is+in+fact+impossible+to+restore+the+original+array+from+this+result

JSON.stringify(["1,",2,3])
//'["1,",2,3]'
//original+array+can+be+restored+exactly|342296|entityMap^0|M|E|14|9|1N|11|2P|3|0|1|3|6|7|K|B|0|0|1|E|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Y|8|@$9|Z|A|10|B|C]|$9|11|A|12|B|C]|$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|17|8|@$9|18|A|19|B|C]|$9|1A|A|1B|B|C]|$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1E|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1F|8|@$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|1I|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1J|8|@]|D|@]|E|$]]|$1|S|3|T|5|6|7|1K|8|@]|D|@]|E|$]]|$1|U|3|V|5|J|7|1L|8|@]|D|@]|E|$K|L]]|$1|W|3|-4|5|6|7|1M|8|@]|D|@]|E|$]]]|X|$]]

Unless you have a custom object with custom <code>.toString</code> method returning <code>JSON.stringify</code> of that object, there is no <code>obj</code> that would give <code>obj.toString() == JSON.stringify(obj)</code>.

When <code>obj</code> is an array like <code>[1,2,3]</code> then <code>.toString()</code> gives:

<pre><code>"1,2,3"
</code></pre>

And <code>JSON.stringify</code>:

<pre><code>"[1,2,3]"
</code></pre>

These are close but not quite the same, the JSON serialized one has no ambiguity with commas and directly runs as Javascript or can be parsed as JSON. 

See:

<pre><code>["1,",2,3].toString();
//"1,,2,3" ... so you can't just split by comma and get original array
//it is in fact impossible to restore the original array from this result

JSON.stringify(["1,",2,3])
//'["1,",2,3]'
//original array can be restored exactly
</code></pre>

blocks|key|124471|text|您可以在JSON.stringify中使用replacer和空格参数，将replacer参数作为函数传递，您可以修改对象和空格参数，这有助于在每个键值对之前提供额外的空格。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|124472|const+replacer+=+(key,+value)+=>+{
++++++++//+Filtering+out+properties
++++++++if+(typeof+value+===+'number')+{
++++++++++++return+1;
++++++++}
++++++++return+value;
++++},

++++foo+=+{
++++++++country:+'India',
++++++++state:+'Gujarat',
++++++++district:+45,
++++++++cm:+'car',
++++++++am:+7
++++},

++++result+=+JSON.stringify(foo,+replacer);

console.log(result)+//+{"country":"India","state":"Gujarat","district":1,"cm":"car","am":1}|code-block|syntax|javascript|124473|空格论点-|124474|const+obj+=+{+a+:+1,+b:2};

const+obj_str+=+JSON.stringify(obj,+null,+'+++++');//+'\t'+gives+one+tab+

console.log(obj_str)|124475|有关更多详细信息，请访问此link.|offset|length|124476|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify^0|0|0|0|0|D|5|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|X|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Y|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Z|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|10|8|@]|9|@$M|11|N|12|1|13]]|A|$]]|$1|O|3|-4|5|6|7|14|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]]]

You can use the replacer and space parameter in JSON.stringify, passing the replacer argument as a function you can modify the object and space parameter helps you to give extra space before every key value pair.

<pre><code>const replacer = (key, value) =&gt; {
 // Filtering out properties
 if (typeof value === 'number') {
 return 1;
 }
 return value;
 },

 foo = {
 country: 'India',
 state: 'Gujarat',
 district: 45,
 cm: 'car',
 am: 7
 },

 result = JSON.stringify(foo, replacer);

console.log(result) // {"country":"India","state":"Gujarat","district":1,"cm":"car","am":1}
</code></pre>

Space argument - 

<pre><code>const obj = { a : 1, b:2};

const obj_str = JSON.stringify(obj, null, ' ');// '\t' gives one tab 

console.log(obj_str)
</code></pre>

For more details you can visit this <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify" rel="nofollow noreferrer">link.</a>

In both the cases I get in output the content of the object:

<pre><code>alert(JSON.stringify(obj));
</code></pre>

or

<pre><code>alert(obj.toString());
</code></pre>

so... what's the difference? what are the advantages or disadvantages of each one?

Are there practical examples to show the difference?

What's the difference in using toString() compared to JSON.stringify()?

JSON

在这两种情况下，我都会输出对象的内容：alert(JSON.stringify(obj));或alert(obj.toString());所以..。有什么关系呢？每种方法的优点或缺点是什么？有没有实际的例子来说明不同之处？

问与使用JSON.stringify()相比，使用toString()有什么不同？
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