Hướng dẫn php flatten associative array

I have an array that has keys and values. For eg:

Array [
    [name] => aalaap
    [age] => 29
    [location] => mumbai
]

I want to convert the keys from this into values, but I want the values to apear right after the keys. For eg:

Array [
    [0] => name
    [1] => aalaap
    [2] => age
    [3] => 29
    [4] => location
    [5] => mumbai
]

I can easily write an iteration function that will do this... for eg:

array_flatten[$arr] {
    foreach [$arr as $arrkey => $arrval] {
        $arr_new[] = $arrkey;
        $arr_new[] = $arrval;
    }
    return $arr_new;
} 

...but I'm trying to find out if there's any way this can be accomplished using array_combine, array_keys, array_values and/or array_merge, preferably in one, so i don't need to use a custom function.

Is there?

asked May 30, 2009 at 7:08

aalaapaalaap

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2

Your own solution is probably the cleanest solution, so converting it to a "one-liner":

$array = array['name' => 'aalaap','age' => 29, 'location' => 'mumbai'];
$answer = array[];

array_walk[$array, create_function['$val,$key', 'global $answer; $answer[]=$key; $answer[]=$val;']];

var_dump[$answer];

This avoids unnecessary and expensive array copies or sorting.

Alternatively, lose the global:

array_walk[$array, create_function['$val,$key,$result', '$result[]=$key; $result[]=$val;'], &$answer];

answered May 30, 2009 at 8:58

Just JulesJust Jules

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2

I don't think this is possible - with the built-in functions you'll end up with all the keys then all the values:

$a = array['a' => 'A', 'b' => 'B', 'c' => 'C'];

$a = array_merge[array_keys[$a], array_values[$a]];
print_r[$a];

You're going to have to use a loop like this:

$b = array[];
foreach [$a as $key => $value]
{
    $b[] = $key;
    $b[] = $value;
}

answered May 30, 2009 at 7:16

GregGreg

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PHP 5.3+ version of Just Jules' answer, and a bit more readable:

array_walk[$array, function[$val, $key] use [&$answer] {
    $answer[] = $key;
    $answer[] = $val;
}];

answered Jun 6, 2014 at 9:23

coatesapcoatesap

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It is possible, but I don't think it is more readable or any faster. It would work with a less-known feature of PHP - the array addition:

$array = array['name' => 'aalaap', 'age' => 29, 'location' => 'mumbai'];

# Separate keys and values into distinct arrays
$keys = array_keys[$array];
$values = array_values[$array];

# Generate 2 new array containing indexes for the 2 arrays which contain
# only odd/even numbers:
$keysKeys = range[0, count[$keys] * 2 - 1, 2];
$valuesKeys = range[1, count[$keys] * 2, 2];

# Combine the keys with the values and add the results:
$array = array_combine[$keysKeys, $keys] + array_combine[$valuesKeys, $values];

# Sort the resulting array, otherwise the numbering will be broken
# [1,3,5,2,4,6]
ksort[$array];

# Result:
var_dump[$array];
array[6] {
    [0]=>
        string[4] "name"
    [1]=>
        string[6] "aalaap"
    [2]=>
        string[3] "age"
    [3]=>
        int[29]
    [4]=>
        string[8] "location"
    [5]=>
        string[6] "mumbai"
}

answered May 30, 2009 at 7:59

soulmergesoulmerge

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2

Could use an array_reduce to get close.

array_reduce[array_keys[$arr], function[$carry, $key]use[$arr]{
    $carry[] = $key;
    $carry[] = $arr[$key];
    return $carry;
}, array[]];

answered Jan 7, 2015 at 0:35