how to use a regular expression to extract json fields?

Question

Beginner RegExp question. I have lines of JSON in a textfile, each with slightly different Fields, but there are 3 fields I want to extract for each line if it has it, ignor

Answer 1

This question is a bit older, but I have had browsed a bit on my PC and found that expression. I passed him as GIST, could be useful to others.

EDIT:

# Expression was tested with PHP and Ruby
# This regular expression finds a key-value pair in JSON formatted strings
# Match 1: Key
# Match 2: Value
# https://regex101.com/r/zR2vU9/4
# http://rubular.com/r/KpF3suIL10

(?:\"|\')(?[^"]*)(?:\"|\')(?=:)(?:\:\s*)(?:\"|\')?(?true|false|[0-9a-zA-Z\+\-\,\.\$]*)

# test document
[
  {
    "_id": "56af331efbeca6240c61b2ca",
    "index": 120000,
    "guid": "bedb2018-c017-429E-b520-696ea3666692",
    "isActive": false,
    "balance": "$2,202,350",
    "object": {
        "name": "am",
        "lastname": "lang"
    }
  }
]