exploding string with multiple delimiter [duplicate] - php

Question

This question already has answers here:
PHP - split String in Key/Value pairs
(5 answers)
Convert backslash-delimited string into an associative array
(4 answers)
Closed 12 months ago.
i have a string like
$str = "1-a,2-b,3-c";
i want to convert it into a single array like this
$array = [
1 => "a",
2 => "b",
3 => "c"
];
what i do is
$str = "1-a,2-b,3-c";
$array = [];
$strex = explode(",", $str);
foreach ($strex as $str2) {
$alphanumeric = explode("-", $str2);
$array[$alphanumeric[0]] = $alphanumeric[1];
}
can i do this in a better way?

Answer 1

You can use preg_match_all for this:
<?php
$str = "1-a,2-b,3-c";
preg_match_all('/[0-9]/', $str, $keys);
preg_match_all('/[a-zA-Z]/', $str, $values);
$new = array_combine($keys[0], $values[0]);
echo '<pre>'. print_r($new, 1) .'</pre>';
here we take your string, explode() it and then preg_match_all the $value using patterns:
/[0-9]/ -> numeric value
/[a-zA-Z]/ -> letter
then use array_combine to get it into one array
Thanks to u_mulder, can shorten this further:
<?php
$str = "1-a,2-b,3-c";
preg_match_all('/(\d+)\-([a-z]+)/', $str, $matches);
$new = array_combine($matches[1], $matches[2]);
echo '<pre>'. print_r($new, 1) .'</pre>';

Answer 2

just a little benchmark:
5000 iterations
Debian stretch, php 7.3
parsed string: "1-a,2-b,3-c,4-d,5-e,6-f,7-g,8-h,9-i"
[edit] Updated with the last 2 proposals [/edit]

Answer 3

You can use preg_split with array_filter and array_combine,
function odd($var)
{
// returns whether the input integer is odd
return $var & 1;
}
function even($var)
{
// returns whether the input integer is even
return !($var & 1);
}
$str = "1-a,2-b,3-c";
$temp = preg_split("/(-|,)/", $str); // spliting with - and , as said multiple delim
$result =array_combine(array_filter($temp, "even", ARRAY_FILTER_USE_KEY),
array_filter($temp, "odd",ARRAY_FILTER_USE_KEY));
print_r($result);
array_filter — Filters elements of an array using a callback function
Note:- ARRAY_FILTER_USE_KEY - pass key as the only argument to callback instead of the value
array_combine — Creates an array by using one array for keys and another for its values
Demo
Output:-
Array
(
[1] => a
[2] => b
[3] => c
)

Answer 4

One way to do with array_map(),
<?php
$my_string = '1-a,2-b,3-c';
$my_array = array_map(function($val) {list($key,$value) = explode('-', $val); return [$key=>$value];}, explode(',', $my_string));
foreach(new RecursiveIteratorIterator(new RecursiveArrayIterator($my_array)) as $k=>$v){
$result[$k]=$v;
}
print_r($result);
?>
WORKING DEMO: https://3v4l.org/aYmOH

Answer 5

Tokens all the way down...
<?php
$str = '1-a,2-b,3-c';
$token = '-,';
if($n = strtok($str, $token))
$array[$n] = strtok($token);
while($n = strtok($token))
$array[$n] = strtok($token);
var_export($array);
Output:
array (
1 => 'a',
2 => 'b',
3 => 'c',
)
Or perhaps more terse without the first if...:
$array = [];
while($n = $array ? strtok($token) : strtok($str, $token))
$array[$n] = strtok($token);

Answer 6

Not a better way but one more example:
$str = "1-a,2-b,3-c";
$arr1 = explode(",", preg_replace("/\-([a-zA-Z]+)/", "", $str));
$arr2 = explode(",", preg_replace("/([0-9]+)\-/", "", $str));
print_r(array_combine($arr1, $arr2));

Answer 7

Mandatory one-liner (your mileage may vary):
<?php
parse_str(str_replace([',', '-'], ['&', '='], '1-a,2-b,3-c'), $output);
var_export($output);
Output:
array (
1 => 'a',
2 => 'b',
3 => 'c',
)

Answer 8

You can do one split on both the , and -, and then iterate through picking off every other pair ($k&1 is a check for an odd index):
<?php
$str = '1-a,2-b,3-c';
foreach(preg_split('/[,-]/', $str) as $k=>$v) {
$k&1 && $output[$last] = $v;
$last = $v;
}
var_export($output);
Output:
array (
1 => 'a',
2 => 'b',
3 => 'c',
)
The preg_split array looks like this:
array (
0 => '1',
1 => 'a',
2 => '2',
3 => 'b',
4 => '3',
5 => 'c',
)

Answer 9

This one explodes the string as the OP has on the comma, forming the pairs: (1-a) and (2-b) etc. and then explodes those pairs. Finally array_column is used to create the associated array:
<?php
$str = '1-a,2-b,3-c';
$output =
array_column(
array_map(
function($str) { return explode('-', $str); },
explode(',', $str)
),
1,
0
);
var_export($output);
Output:
array (
1 => 'a',
2 => 'b',
3 => 'c',
)