从给定数组的公共第一个索引值中查找数组中的值并对其进行分组

Question

Suppose I have this multidimensional array:

Array(

[0] => Array
    (
        [0] => 08/Mar/2004
        [1] => apple
    )

[1] => Array
    (
        [0] => 08/Mar/2004
        [1] => orange
    )

[2] => Array
    (
        [0] => 09/Mar/2004
        [1] => mango
    )

[3] => Array
    (
        [0] => 09/Mar/2004
        [1] => grape
    )

[4] => Array
    (
        [0] => 10/Mar/2004
        [1] => apple
    )

[5] => Array
    (
        [0] => 10/Mar/2004
        [1] => kiwi
    )
)

The dates present in the array are unknown, meaning that the array can have other date such as 11/Mar/2004 and 12/Mar/2004 and so on at each first position of the sub array.

An array should be dynamically created for every different date present.

I want to retrieve all the value at index 1 from the sub arrays for all the common dates and save the values in the newly created array for the corresponding date.

I want the result to be as follows:

Array(
    [0] => 08/Mar/2004
    [1] => apple
    [2] => orange
)

Array(
    [0] => 09/Mar/2004
    [1] => mango
    [2] => grape
)

Array(
    [0] => 10/Mar/2004
    [1] => apple
    [2] => kiwi
)

Any help would be much appreciated.

Answer 1

This should do it:

foreach($array as $value)  {
    if(!isset($result[$value[0]])) {
        $result[$value[0]][] = $value[0];
    }
    $result[$value[0]][] = $value[1];
}

$result = array_values($result);

Loop the array and build a result array:

• If the result with date as key does not exist then create it and add the date
• Then append the fruit
• Finally, re-index if needed