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phparrayssortingstable-sort

Stable sort an array of pipe-delimited strings only by the leading value

I have an array that contains entries that themselves contain two types of entries.

For simplicity sake, let's say that the entries are like this:

a|1
b|4
a|2
c|5
b|3

etc.

In fact they represent categories and subcategories in my database.

I will use explode to break these entries into letters and digits.

The question is: I want to group them by category.

What's the easiest way to create a multilevel array, which could be sorted by letters:

a|1
a|2
b|4
b|3
c|5

?

Solution

  • How about something like this?

    $input  = array('a|1','b|4','a|2','c|5','b|3');
$output = array();

foreach($input as $i){

    list($key,$val) = explode("|",$i);
    $output[$key][] = $val;

}

    Output:

    Array
(
[a] => Array
    (
        [0] => 1
        [1] => 2
    )

[b] => Array
    (
        [0] => 4
        [1] => 3
    )

[c] => Array
    (
        [0] => 5
    )

)