Find JSON strings in a string

by

Extracting the JSON string from given text

Since you’re looking for a simplistic solution, you can use the following regular expression that makes use of recursion to solve the problem of matching set of parentheses. It matches everything between { and } recursively.

Although, you should note that this isn’t guaranteed to work with all possible cases. It only serves as a quick JSON-string extraction method.

$pattern = '
/
\{              # { character
    (?:         # non-capturing group
        [^{}]   # anything that is not a { or }
        |       # OR
        (?R)    # recurses the entire pattern
    )*          # previous group zero or more times
\}              # } character
/x
';

preg_match_all($pattern, $text, $matches);
print_r($matches[0]);

Output:

Array
(
    [0] => {"action":"product","options":{...}}
    [1] => {"action":"review","options":{...}}
)

Regex101 Demo

Validating the JSON strings

In PHP, the only way to know if a JSON-string is valid is by applying json_decode(). If the parser understands the JSON-string and is according to the defined standards, json_decode() will create an object / array representation of the JSON-string.

If you’d like to filter out those that aren’t valid JSON, then you can use array_filter() with a callback function:

function isValidJSON($string) {
    json_decode($string);
    return (json_last_error() == JSON_ERROR_NONE);
}

$valid_jsons_arr = array_filter($matches[0], 'isValidJSON');

Online demo

More Related Contents:

  1. How to remove array index from json object while convert array to jsonobject php? [closed]
  2. Turn Plain Text URLs into Active Links using PHP [closed]
  3. how to read Json values [closed]
  4. How do I generate a JSON file from PHP array? [duplicate]
  5. How to Convert string response to array laravel
  6. deny direct access to a folder and file by htaccess
  7. Convert plain text URLs into HTML hyperlinks in PHP
  8. Why does the PHP json_encode function convert UTF-8 strings to hexadecimal entities?
  9. Remove style attribute from HTML tags
  10. “vertical” regex matching in an ASCII “image”
  11. Regular expression pattern to match URL with or without http://www
  12. Match a^n b^n c^n (e.g. “aaabbbccc”) using regular expressions (PCRE)
  13. handle json request in PHP
  14. Parsing CSS by regex
  15. Android JSON HttpClient to send data to PHP server with HttpResponse
  16. Codeigniter Routes regex – using dashes in controller/method names
  17. Get the price of an item on Steam Community Market with PHP and Regex
  18. Sending HTML Code Through JSON
  19. Laravel preg_match(): No ending delimiter ‘/’ found
  20. json decode in php
  21. How to prefix a positive number with plus sign in PHP
  22. How to insert json array into mysql database
  23. Regex / DOMDocument – match and replace text not in a link
  24. Converting Javascript Regex to PHP
  25. Extract floating point numbers from a delimited string in PHP
  26. Parse math operations with PHP
  27. How to validate phone number using PHP? [duplicate]
  28. What does [\S\s]* mean in regex in PHP?
  29. UTF-8 in PHP regular expressions [duplicate]
  30. Validate date format in php

Leave a Comment