array_push add value to an existing key

Question

I have the following array called $zoo

Array
(
[0] => &dog&
[1] => *1*
[2] => one
[3] => &cat&
[4] => *2*
[5] => two
[6] => &mouse&
[7] => *3*
[8] => three
[9] => &dog&
[10] => *4*
[11] => four
)

and i need the following result:

Array
(
[&dog&] => Array
    (
        [0] => Array
            (
                [0] => *1*
                [1] => one
            )
        [1] => Array
            (
                [0] => *4*
                [1] => four
            )
    )
[&cat&] => Array
    (
        [0] => Array
            (
                [0] => *2*
                [1] => two
            )
    )
[&mouse&] => Array
    (
        [0] => Array
            (
                [0] => *3*
                [1] => three
            )
    )
)

This is what I have come up with but the problem is that for [&dog&] he gives me only the last value (namely 4, four) and not the first value (1, one)

$animals=array();
for ($i = 0; $i < count($zoo); $i++)
{
if($zoo[$i][0] === "&")
    {
    $name=$zoo[$i];
    if (isset($name))
        $animals[$name] = array($liste);
    else
        $animals[$name] = array($liste);
    $liste="";
    }
if($zoo[$i][0] !== "&")
    {        
    $number = $zoo[$i];
    $liste[] = $number;
    $animals[$name] = array($liste);
    }
}
print_r($animals);

this results in

Array
(
[&dog&] => Array
    (
        [0] => Array
            (
                [0] => *4*
                [1] => four
            )
    )
[&cat&] => Array
    (
        [0] => Array
            (
                [0] => *2*
                [1] => two
            )
    )
[&mouse&] => Array
    (
        [0] => Array
            (
                [0] => *3*
                [1] => three
            )
    )
)

can anyone point me in the good direction?

My solution does work as intended. . . let me know if it isn't enough for you. — Levi Morrison
– Levi Morrison, Commented Oct 13, 2011 at 8:24
@levi : this is exactly what I need. Let me add a problem with the following array: Array ( [0] => 1 [1] => &dog& [2] => one [3] => 2 [4] => &cat& [5] => two [6] => 3 [7] => &mouse& [8] => three [9] => 4 [10] => &dog& [11] => four ) and I need the SAME RESULT. so now the word between & still has to be the key but the number between * that precedes the word between & should be the first element of the array in the value. — Preys
– Preys, Commented Oct 13, 2011 at 13:17

AndreKR · Accepted Answer · 2011-10-13 12:33:09Z

2

$animals = array();

$c = count($zoo)/3;
for ($i = 0 ; $i < $c ; $i++)
{
    $species = array_shift($zoo);
    $number = array_shift($zoo);
    $number_text = array_shift($zoo);

    $animals[$species] []= array($number, $number_text);
}

If you want the start of a new animal be triggered by the "&" in the text, there are several solutions. Here's mine:

$animals = array();
unset($current_animal);
foreach ($zoo as $text)
{
    if ($text{0} == '&')
    {
        // Insert an element for the new animal and get a reference to it
        $animals[$text] []= array();
        end($animals[$text]);
        $current_animal =& $animals[$text][key($animals[$text])];
    }
    else
        $current_animal []= $text;
}
unset($current_animal);

edited Oct 13, 2011 at 12:33

answered Oct 12, 2011 at 21:17

AndreKR

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6 Comments

Levi Morrison Over a year ago

Brittle, what if he has more than two values associated with each new key?

Levi Morrison Over a year ago

@herbert And where does it say that? Sure, he asked with that example, but it's clear from his implementation that he was searching based on &.

Herbert Over a year ago

@Levi: It's clear from his question that he has an array in one form and wants it in another form. The OP never said it was an example. If it is then the OP needs to specify that.

Levi Morrison Over a year ago

@Herbert, I'm not going to argue it, but that looks a lot like sample data. . .

Herbert Over a year ago

@Levi: I agree to disagree since the OP hasn't chimed in one way or the other.

|

Levi Morrison · Accepted Answer · 2011-10-13 20:09:38Z

1

A solution that works for an array that has any number of indices that should grouped. It simply searches for a & prefix and adds the new values to the animals entry.

    $zooAmp = array(
            '&dog&',
            '*1*',
            'one',
            '&cat&',
            '*2*',
            'two',
            '&mouse&',
            '*3*',
            'three',
            '&dog&',
            '*4*',
            'four'
    );

    $zooStar = array(
            '*1*',
            '&dog&',
            'one',
            '*2*',
            '&cat&',
            'two',
            '*3*',
            '&mouse&',
            'three',
            '*4*',
            '&dog&',
            'four'
    );

    function & refactor(array $unfactored) {
            $len = count($unfactored);
            $data = array();

            if ($len<3) {
                    return $data;
            }

            if ($unfactored[0][0]=='&') {
                    //this algorithm isn't too bad, just loop through and add the ones starting with
                    //'&' to the data, and write everything from that index down to the next '&'
                    //into the created index in data.

                    $i=0;
                    while ($i<$len) {
                            if (!array_key_exists($unfactored[$i], $data))
                                    $data[$unfactored[$i]] = array();

                            //save to $arr for easier reading and writing
                            $arr = &$data[$unfactored[$i]];

                            $index = count($arr);
                            $arr[$index] = array();

                            for ($c=$i+1; $c<$len && $unfactored[$c][0]!='&'; $c++) {
                                    $arr[$index][] = $unfactored[$c];
                            }


                            $i = $c;
                    }

            } elseif ($unfactored[0][0]=='*') {
                    //this algorithm is a bit harder, but not so bad since we've already done the
                    //basic algorithm above.  We just need to store the ones with a '*' and then
                    //add them back into the array after it's been created.

                    $i=0;
                    $unorganizedItem = NULL;

                    while ($i<$len) {
                            $key = $unfactored[$i];

                            if ($key[0]=='*') {
                                    $unorganizedItem = $key;
                                    $i++;
                            } elseif ($key[0]=='&') {
                                    if(!array_key_exists($key, $data))
                                            $data[$key] = array();

                                    //save to $arr for easier reading and writing
                                    $arr = &$data[$key];
                                    $index = count($arr);

                                    $arr[$index][] = $unorganizedItem;
                                    $unorganizedItem = null;

                                    for ($c=$i+1; $c<$len && $unfactored[$c][0]!='&'; $c++) {
                                            if ($unfactored[$c][0]=='*') {
                                                    $unorganizedItem = $unfactored[$c];
                                            } else {
                                                    $arr[$index][] = $unfactored[$c];
                                            }
                                    }

                                    $i = $c;

                            }
                    }

            }

            return $data;

    }

    print_r(refactor($zooAmp));
    print_r(refactor($zooStar));

Prints:

Array
(
    [&dog&] => Array
        (
            [0] => Array
                (
                    [0] => *1*
                    [1] => one
                )

            [1] => Array
                (
                    [0] => *4*
                    [1] => four
                )

        )

    [&cat&] => Array
        (
            [0] => Array
                (
                    [0] => *2*
                    [1] => two
                )

        )

    [&mouse&] => Array
        (
            [0] => Array
                (
                    [0] => *3*
                    [1] => three
                )

        )

)
Array
(
    [&dog&] => Array
        (
            [0] => Array
                (
                    [0] => *1*
                    [1] => one
                )

            [1] => Array
                (
                    [0] => *4*
                    [1] => four
                )

        )

    [&cat&] => Array
        (
            [0] => Array
                (
                    [0] => *2*
                    [1] => two
                )

        )

    [&mouse&] => Array
        (
            [0] => Array
                (
                    [0] => *3*
                    [1] => three
                )

        )

)

edited Oct 13, 2011 at 20:09

answered Oct 12, 2011 at 21:22

Levi Morrison

19.6k8 gold badges69 silver badges87 bronze badges

12 Comments

Herbert Over a year ago

Good robust and general solution. +1

Preys Over a year ago

@levi : this is exactly what I need. Let me add a problem with the following array: Array ( [0] => 1 [1] => &dog& [2] => one [3] => 2 [4] => &cat& [5] => two [6] => 3 [7] => &mouse& [8] => three [9] => 4 [10] => &dog& [11] => four ) and I need the same result. so now the word between & still has to be the key but the word between * should be the first element of array in the value.

Levi Morrison Over a year ago

@Preys, does it need to be the same function? And will the two formats ever mix?

Preys Over a year ago

@Levi no, these are two independant functions. They will not mix.

Levi Morrison Over a year ago

@Preys, can we assume that each sub-array will have the same number of elements? Meaning, &dog&[0] will have the same number of elements as &dog&[1]?

|

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