How to get an array in a string in php?

Question

If I have a string like this ,

$my_string="array('red','blue')";

How can I convert this to a real array ?

Example. :

$my_array=array('red','blue');

For this purpose, you can use `eval` function... but its use is not reccomended. — Pipe, Jan 20 '17 at 12:43
@Rizier123, `array('red','blue')` is not a print_r output... i don't think its a duplicate question. — Pipe, Jan 20 '17 at 12:45
The bigger question is why you have such a string in the first place. If you want to serialise values, you should choose another format which is readily unserialisable; e.g. JSON. — deceze, Jan 20 '17 at 12:57
@deceze I'm getting outputs from an app , only way I can communicate with the app is through strings , I want to check those strings are arrays if(is_array($string)) I have to run different set of functions, if its just a string I have to run something else , so will I be able to detect the string is a json object if I use json_encode in the app? — DivParser, Jan 20 '17 at 13:09
Yes, PHP source code is not an appropriate *data interchange format*. That's exactly what things like JSON were invented for. — deceze, Jan 20 '17 at 13:10

score 2 · Accepted Answer · edited May 23 '17 at 12:16

DO NOT USE EVAL. That is terrible overkill and very probably extremely unsafe.

While this is not the BEST way of doing this (as mentioned in question comments), you can use this below function to do exactly what you need.

How it works:

It uses Regex to find and split the string based on these layouts, the array is split using preg_split which is a regex verson of the more popular explode.

Once split the array will have some blank values so simply use array_filter to remove these blank values.

so:

    // Explode string based on regex detection of:
    //
    // (^\h*[a-z]*\h*\(\h*')
    // 1) a-z text with spaces around it and then an opening bracket
    // ^ denotes the start of the string
    // | denotes a regex OR operator. 
    // \h denotes whitespace, * denotes zero or more times.
    //
    // ('\h*,\h*')
    // 2) or on '),(' with possible spaces around it
    //
    // ('\h*\)\h*$)
    // 3) or on the final trailing '), again with possible spaces.
    // $ denotes the end of the string
    // the /i denotes case insensitive. 

function makeArray($string){

    $stringParts = preg_split("/(^\h*[a-z]*\h*\(\h*')|('\h*,\h*')|('\h*\)\h*$)/i",$string);
    // now remove empty array values. 
    $stringParts = array_filter($stringParts);
    return $stringParts;
  }

Usage:

//input
$myString = " array('red','blue')";
//action
$array = makeArray($myString);
//output
print_r($array);

Output:

Array (
[1] => red
[2] => blue
)

Example 2:

$myString = " array('red','blue','horses', 'crabs (apples)', '(trapdoor)', '<strong>works</strong>', '436')";
$array = makeArray($myString);
print_r($array);

Output:

Array (
[1] => red
[2] => blue
[3] => horses
[4] => crabs (apples)
[5] => (trapdoor)
[6] => <strong>works</strong>
[7] => 436
)

Obviously the regex may need slight tweaking based on your exact circumstances but this is a very good starting point...

Reference Question/Answers

How to get an array in a string in php?

1 Answers1