如何在不使用 Try/Catch 的情况下检查字符串是否是 JavaScript 中的有效 JSON 字符串

2022-01-31 00:00:00 json javascript

类似:

var jsonString = '{ "Id": 1, "Name": "Coke" }';

//should be true
IsJsonString(jsonString);

//should be false
IsJsonString("foo");
IsJsonString("<div>foo</div>")

解决方案不应包含 try/catch.我们中的一些人打开了中断所有错误",他们不喜欢调试器中断那些无效的 JSON 字符串.

The solution should not contain try/catch. Some of us turn on "break on all errors" and they don't like the debugger breaking on those invalid JSON strings.

推荐答案

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 )

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