How to declare an array using a string

Question

Let's say I've uploaded this string into a database

"Red", "Blue", "Orange", "Green"

Now I've set it into a variable which I call strColorArray:

$strColorArray = '"Red", "Blue", "Orange", "Green"';

I can't seem to get it to work the way I want it to when I put it in an array, I wondering if there is an easy to understand way to fix this.

$strColorArray = '"Red", "Blue", "Orange", "Green"';
$colorArray =  array($strColorArray);
echo $colorArray[0];

Currently

echo $colorArray[0]; gives "Red", "Blue", "Orange", "Green"

I would like it to have $colorArray[0] as Red, $colorArray[1] as Blue, and so on.

Evert · Accepted Answer · 2016-07-23 19:24:26Z

3

You need to use the explode() function to convert a string to array. In your case, you might need to do something more:

$strColorArray = '"Red", "Blue", "Orange", "Green"';
$strColorArray = str_replace(array('"', ', '), array("", ","), $strColorArray); // Remove the spaces and double quotes
$colorArray = explode(",", $strColorArray);

When I give var_dump($colorArray) (to check the contents of a variable), I get this output:

array(4) {
  [0]=>
  string(3) "Red"
  [1]=>
  string(4) "Blue"
  [2]=>
  string(6) "Orange"
  [3]=>
  string(5) "Green"
}

Output: http://ideone.com/3MhGle

edited Jul 23, 2016 at 19:24

Evert

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answered Jul 23, 2016 at 18:49

Praveen Kumar Purushothaman

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Comments

Raj · Accepted Answer · 2016-07-23 19:09:45Z

0

$strColorArray = '"Red", "Blue", "Orange", "Green"';
$stripper =  str_replace(array("'",'"'),'',$strColorArray);
$colorArray = explode(',',$stripper);
echo $colorArray[0];

answered Jul 23, 2016 at 19:09

Raj

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2 Comments

Blue Over a year ago

While this code snippet may solve the question, including an explanation really helps to improve the quality of your post. Remember that you are answering the question for readers in the future, and those people might not know the reasons for your code suggestion. Please also try not to crowd your code with explanatory comments, as this reduces the readability of both the code and the explanations!

Raj Over a year ago

@FrankerZ Thanks for your suggestion.

RomanPerekhrest · Accepted Answer · 2016-07-23 19:14:43Z

0

"One-line" solution using preg_match_all function:

preg_match_all("/\w+/i", $strColorArray, $matches);

print_r($matches[0]);

The output:

Array
(
    [0] => Red
    [1] => Blue
    [2] => Orange
    [3] => Green
)

http://php.net/manual/en/function.preg-match-all.php

edited Jul 23, 2016 at 19:14

answered Jul 23, 2016 at 18:58

RomanPerekhrest

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3 Comments

RomanPerekhrest Over a year ago

@PraveenKumar, you have confused, it's not JavaScript regex

Praveen Kumar Purushothaman Over a year ago

Oh, so JavaScript only has g, is it? :P

RomanPerekhrest Over a year ago

@PraveenKumar, I wouldn't say that ONLY javascript regexpes have g modifier, maybe other languages have it too. But, there's no g modifier for PHP regexp functions

Evert · Accepted Answer · 2016-07-23 19:25:40Z

0

Here's another approach that doesn't use regexes:

$out = array_map(
   function($item) {
      return trim($item, '" ');
   },
   explode(',', $in)
);

answered Jul 23, 2016 at 19:25

Evert

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Comments

AbraCadaver · Accepted Answer · 2016-07-23 19:23:37Z

-1

So long as you are in control of the data going in and coming out of the database, then this is a simple way given that format:

eval("\$colorArray = [$strColorArray];");

Or for older PHP versions:

eval("\$colorArray = array($strColorArray);");

answered Jul 23, 2016 at 19:23

AbraCadaver

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1 Comment

Evert Over a year ago

It works for the sample, but still a pretty bad suggestion. Even if you 'control' the data, it doesn't mean that the real data will not contain $ or one of the many other characters that breaks this.

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