如何从输入字符串创建包含键值对的数组数组？

Question

I am developing a search bar in php, but can't write a regex expression that can do what I require.

I have an input string like this:

$text = "key1=value 1 key2=value 2 key3=val 3";

I would like to be able to split into a multi-dimensional array with this structure:

$array = [["key1", "value 1"], ["key2", "value 2"], ["key3", "val 3"]];

How can this be done with a regex pattern in php?

Answer 1

Here are two ways to generate your desired multidimensional array of key-value pairs with preg_split()...

(Demo)

Approach #1: Split on = or space followed by 1 or more word characters then a =

var_export(array_chunk(preg_split('~=| (?=\w+=)~', $text), 2));

Approach #2: Split on each key, include leading&training characters in match, retain only keys & values

var_export(array_chunk(preg_split('~ ?(\w+)=~', $text, null, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE), 2));

Output: (from either)

array (
  0 => 
  array (
    0 => 'key1',
    1 => 'value 1',
  ),
  1 => 
  array (
    0 => 'key2',
    1 => 'value 2',
  ),
  2 => 
  array (
    0 => 'key3',
    1 => 'val 3',
  ),
)

preg_split() can only return a single dimensional array (in this case, key, val, key, val, ...), so array_chunk() is used to generate the desired two-elements-per-subarray structure.