How Can I Convert a String of Key-Value Pairs into an Associative Array in PHP?

Converting a String of Key-Value Pairs into an Associative Array

Problem:
You have a string formatted like "key1value1key2value2key3value3", and you want to convert it into an associative array, where "key1" maps to "value1", "key2" maps to "value2", and so on.

Solution Using Regular Expressions:

The quickest and most straightforward solution involves using a regular expression and array_combine:

preg_match_all("/([^\\]+)\\([^\\]+)/", $string, $p);
$array = array_combine($p[1], $p[2]);

This regex identifies adjacent key-value pairs separated by backslashes. The captured groups are then merged into an array using array_combine.

Adapting to Different Delimiters:

This approach can be easily adapted to handle different key-value and pair delimiters. For instance:

# Key/value separated by colons, pair by commas
preg_match_all("/([^:]+):([^,]+)/", $string, $p);
$array = array_combine($p[1], $p[2]);

Allowing Varying Delimiters:

To permit different delimiters within a single string, a more flexible regex can be used:

preg_match_all("/([^:=]+)[:=]+([^,+&]+)/x", $string, $p);

Other Approaches:

parse_str() with String Replacement:

If the input string already follows the key=value&key2=value2 format, you can use parse_str:

parse_str(strtr($string, ":,", "=&"), $pairs);

Manual Key/Value Separation:

While it's often longer, you can also manually create an array using explode and foreach:

$pairs = array_combine(explode("\", $string, 2, TRUE), explode("\", $string, 2, TRUE));

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