Split string with only one delimiting character into key-value pairs

Question

I have a colon-delimited string like this:

"Part1:Part2:Part3:Part4"

With explode I can split the string into an array:

echo '<pre>';
print_r(explode(":", "Part1:Part2:Part3:Part4"));
echo '</pre>';

Output:

Array
(
    [0] => Part1
    [1] => Part2
    [2] => Part3
    [3] => Part4
)

But I need associative array elements like this:

Array
    (
        [Part1] => Part2
        [Part3] => Part4
    )

UPDATE

echo '<pre>';
list($key, $val) = explode(':', 'Part1:Part2:Part3:Part4');
$arr= array($key => $val);
print_r($arr);
echo '</pre>';

Result:

Array
(
    [Part1] => Part2
)

Does this answer your question? [explode() into $key=>$value pair](https://stackoverflow.com/questions/15966693/explode-into-key-value-pair) — zoldxk, Apr 28 '21 at 15:35
I'm just wondering why your pairs aren't separated by a different delimiter. Do you have control over the generation of that string? — El_Vanja, Apr 28 '21 at 15:44
See also [this question](https://stackoverflow.com/questions/49563864/how-to-convert-a-string-to-a-multidimensional-recursive-array-in-php) — Syscall, Apr 28 '21 at 15:49

score 0 · Answer 1 · answered Apr 28 '21 at 16:07

Alternative solution using only array_* functions.

Collect all values that are going to be keys for the resultant array.
Collect all values that are going to be actual values for the resultant array.
Combine both using array_combine().

Snippet:

<?php

$str = "Part1:Part2:Part3:Part4";

$res = array_combine(
        array_map(fn($v) => $v[0], array_chunk(explode(':',$str),2)),
        array_map(fn($v) => $v[1], array_chunk(explode(':',$str),2))
);

score 0 · Answer 2 · answered Apr 28 '21 at 20:46

Using a for loop, you could also use the modulo operator % and create the key in the if part.

The if clause will be true for the first item having the key first and then the value in the else part, toggeling the keys and the values.

$str = "Part1:Part2:Part3:Part4";
$parts = explode(':', $str);
$result = [];

for ($i = 0; $i < count($parts); $i++) {
    $i % 2 === 0 ? $k = $parts[$i] : $result[$k] = $parts[$i];
}    
print_r($result);

Output

Array
(
    [Part1] => Part2
    [Part3] => Part4
)

See a php demo

score -1 · Accepted Answer · answered Apr 28 '21 at 15:44

Try this

$string = "Part1:Part2:Part3:Part4";
$arr = explode(":", $string);

$key = "";
$i = 0;
$newArray = [];
foreach($arr as $row){
    if($i == 0){
        $key = $row;
        $i++;
    } else {
        $newArray[$key] = $row;
        $i = 0;
    }
}

echo "<pre>";
print_r($newArray);
echo "</pre>";

Split string with only one delimiting character into key-value pairs

3 Answers3