在JSON响应jQuery的单引号 [英] jQuery single quote in JSON response

问题描述

我使用的是发出请求到服务器 jQuery.post（）和我的服务器返回的JSON对象（如 {变种： 值，...} 。但是，如果任何一个值，包含一个单引号（正确转义像 \ ），jQuery的失败解析一个非常有效的JSON字符串这里是我的意思（在Chrome的控制台做）的一个例子：

I'm making requests to my server using jQuery.post() and my server is returning JSON objects (like { "var": "value", ... }. However, if any of the values contains a single quote (properly escaped like \'), jQuery fails to parse an otherwise valid JSON string. Here's an example of what I mean (done in Chrome's Console):

这是正常的吗？有没有办法通过JSON正确地传递一个单引号？

Is this normal? Is there no way to properly pass a single quote via JSON?

推荐答案

据有关 JSON网站状态机图，只逃脱双引号字符是允许的，不是单引号。单引号字符不需要进行转义：

According to the state machine diagram on the JSON website, only escaped double-quote characters are allowed, not single-quotes. Single quote characters do not need to be escaped:

更新 - 对于那些有兴趣的更多信息：

Update - More information for those that are interested:

道格拉斯·克罗克福德并没有具体说出为什么JSON规范不允许转义字符串中的单引号。然而，在他的 JavaScript的附录E：好的部分的，他写道：

Douglas Crockford does not specifically say why the JSON specification does not allow escaped single quotes within strings. However, during his discussion of JSON in Appendix E of JavaScript: The Good Parts, he writes:

JSON的设计目标是微乎其微，便携式，文本和JavaScript的一个子集。我们需要达成一致，以实现互操作越少，越容易就可以实现互操作。

JSON's design goals were to be minimal, portable, textual, and a subset of JavaScript. The less we need to agree on in order to interoperate, the more easily we can interoperate.

因此​​，也许，他决定只允许使用双引号，因为这是一个都不能少，所有的JSON的实现都必须同意的规则来定义字符串。其结果，这是不可能的一字符串中一个单引号字符意外终止串，因为根据定义，一个串只能由一个双引号字符终止。因此，没有必要让在正式的规范逃逸单引号的。

So perhaps he decided to only allow strings to be defined using double-quotes since this is one less rule that all JSON implementations must agree on. As a result, it is impossible for a single quote character within a string to accidentally terminate the string, because by definition a string can only be terminated by a double-quote character. Hence there is no need to allow escaping of a single quote character in the formal specification.

---

挖一点点更深，克罗克福德的 org.json 以Java实现的JSON是更允许和确实的允许单引号字符：

---

Digging a little bit deeper, Crockford's org.json implementation of JSON for Java is more permissible and does allow single quote characters:

用的toString方法产生的文本严格遵循JSON语法规则。构造函数是更宽容的文本，他们将接受：

The texts produced by the toString methods strictly conform to the JSON syntax rules. The constructors are more forgiving in the texts they will accept:

...

  
• 在字符串可以用'（单引号）引用。
  

这是由 JSONTokener 源$ C ​​$ C证实。该 nextString 方法接受转义单引号和对待他们就像双引号字符：

This is confirmed by the JSONTokener source code. The nextString method accepts escaped single quote characters and treats them just like double-quote characters:

public String nextString(char quote) throws JSONException {
    char c;
    StringBuffer sb = new StringBuffer();
    for (;;) {
        c = next();
        switch (c) {

        ...

        case '\\':
            c = this.next();
            switch (c) {

            ...

            case '"':
            case '\'':
            case '\\':
            case '/':
                sb.append(c);
                break;
        ...

在方法的顶部是一个内容的评论：

At the top of the method is an informative comment:

正式JSON格式不允许在单引号的字符串，而是一个实现允许接受它们。

The formal JSON format does not allow strings in single quotes, but an implementation is allowed to accept them.

因此​​，一些实施将接受单引号 - 但你不应该依赖于这一点。许多流行的实现是非常严格在这方面并拒绝JSON包含单引号字符串和/或转义单引号。

So some implementations will accept single quotes - but you should not rely on this. Many popular implementations are quite restrictive in this regard and will reject JSON that contains single quoted strings and/or escaped single quotes.

最后，以配合该回到原来的问题， jQuery.parseJSON 使用浏览器的原生JSON解析器或加载库的第一次尝试，如的 json2.js 在适用情况下（这在一个侧面说明是jQuery的逻辑是基于如果 JSON库没有定义）。因此，jQuery的只能是作为许可作为底层的实现：

Finally to tie this back to the original question, jQuery.parseJSON first attempts to use the browser's native JSON parser or a loaded library such as json2.js where applicable (which on a side note is the library the jQuery logic is based on if JSON is not defined). Thus jQuery can only be as permissive as that underlying implementation:

parseJSON: function( data ) {
    ...

    // Attempt to parse using the native JSON parser first
    if ( window.JSON && window.JSON.parse ) {
        return window.JSON.parse( data );
    }

    ...

    jQuery.error( "Invalid JSON: " + data );
},

据我所知，这些实现只能坚持到官方JSON规范不接受单引号，因此同样没有jQuery的。

As far as I know these implementations only adhere to the official JSON specification and do not accept single quotes, hence neither does jQuery.

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