使用正则表达式从文件中提取JSON键值映射

Question

I'm not really strong in regexes and tried to solve a problem with a parser written by hands, my own bicycle, which failed on some inputs unpredicted by me though, the problem is as follows: I have JavaScript i18n files that, along with translations, contain some other configuration stuff that may be defined somewhere in a file (that's the main reason why it's pretty hard to handle the problem with hand made parser), so the file is something like that:

(function() {
    'use strict';
    //some configuration stuff (some other stuff may be insterted)
    var translations = angular.module('module.translations.languages.enUs', []);

    translations.constant('translationsName', {
     "first_label":"first_label_value",
     "second_label":"second_label_value"
     //etc
});

}());

The example above is only one of possible template options, but they all have one thing in common - translation labels are defined as a key-value json which is nothing but a java map serialized to json. My goal is to get only these key-value json from a file, deserialize it to map, do some operations with it and insert it back again. So the question is: perhaps someone has ready and proven regex that could handle this kind of situation - find a map of key-value json in a text? If so, I would be really grateful for that! Thanks, Cheers, Andrey

Answer 1

You could use this regexp to find "key":"value" pairs :

"([^"]+)"\\s*:\\s*"([^"]+)",?

Group 1 is the key, Group 2 is the value

It will also find "key": "value" , "key" :"value" or "key" : "value" pairs.

Demo on regexplanet (click the Java button then click Test button)

Also a demo on regex101

Explanation

"([^"]+)" : Capture any character but a double-quote between double-quotes (this is the key )

\\s*? : Followed by zero or more whitespace

\\s* : Followed by a colon

\\s* : Followed by zero or more whitespace

"([^"]+)" : Capture any character but a double-quote between double-quotes (this is the value )