CODEWITHSUNDEEP
phparraysstringparsing
Obaid
Obaid

Reputation: 21

How to convert array-like string to an associative array?

I want to use array syntax inside a string value and then add that variable in array().

Like:

$value= "'user_type'=>'test','username'=>'test'";
$form_data = array($value);

The desired assignment should be: 

$form_data = array('user_type'=>'test','username'=>'test');

but this is not what I get.

Upvotes: 1

Views: 616

Answers (2)

mickmackusa
mickmackusa

Reputation: 47992

This is a method using parse_str() -- which is an intuitive, loop-free one-liner. It seems like the best choice to me -- I mean this is the very purpose of the function! Like any robust solution for this task, it does need careful preparation.

Code: (Demo)

$value= "'user_type'=>'test1','username'=>'test2','monkey\'s wrench'=>'that\'s trouble'";
parse_str(stripslashes(str_replace(["'=>'","','"],['=','&'],trim($value,"'"))),$form_data);  // second param is output variable
var_export($form_data);

This will serve you well, unless your "keys" or "values" contain the delimiting substrings.

  • First the leading and trailing single quotes are trimmed off
  • Then str_replace() will modify the delimiters:
    • '=>' becomes =
    • ',' becomes &
  • Then stripslashes() handles any escaping slashes.
  • Finally, parse_str() works its magic to directly produce the associative array.

My method will not work out-of-the-box on the duplicate link on the question because of the (string) prefix and the optional spacing around the delimiting commas. My method is specifically suited to this strictly-structured, one-dimensional, associative, array-like string.

A method using preg_match() with a carefully designed pattern may be trustworthy, but regex is categorically slower than string functions and may appear a little convoluted to the untrained eye.

A method using eval() is possible as well, but that function should only be used as a "Plan Z" when all else fails to do the job well AND the values need to be heavily validated/filtered with extreme prejudice.

A method using explode() and a foreach() loop will require a larger code block and I assume it will be a slower alternative (but maybe not). Exploding on any single character will run a higher risk of mangling data; like with all solutions extra attention to preserving data intregity is essential.

verjas' method seems a logical approach, but when replacing single quotes with double quotes, keys and values that contain quotes may get mangled. I will leave the preparation code to verjas to accommodate single and double quotes.

Upvotes: 0

verjas
verjas

Reputation: 1793

I would use a JSON transformation. This should work:

// create a JSON string like:
$value = '{ "user_type":"test", "username":"test" }';
$form_data = json_decode($value, true);
// test it
var_dump($form_data);

Upvotes: 2

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