先评论.问题是关于不使用 try/catch.
如果您不介意使用它，请阅读下面的答案.这里我们只是使用一个正则表达式检查一个 JSON 字符串，它在大多数情况下都可以工作，而不是所有情况.

A comment first. The question was about not using try/catch.
If you do not mind to use it, read the answer below. Here we just check a JSON string using a regexp, and it will work in most cases, not all cases.

查看 https://github 中的第 450 行.com/douglascrockford/JSON-js/blob/master/json2.js

有一个用于检查有效 JSON 的正则表达式，例如:

There is a regexp that check for a valid JSON, something like:

if (/^[],:{}s]*$/.test(text.replace(/\["\/bfnrtu]/g, '@').
replace(/"[^"\

]*"|true|false|null|-?d+(?:.d*)?(?:[eE][+-]?d+)?/g, ']').
replace(/(?:^|:|,)(?:s*[)+/g, ''))) {

  //the json is ok

}else{

  //the json is not ok

}

编辑:新版本的 json2.js 进行了比上面更高级的解析，但仍然基于正则表达式替换(来自 @Mrchief 的评论)

EDIT: The new version of json2.js makes a more advanced parsing than above, but still based on a regexp replace ( from the comment of @Mrchief )