Set array element using another array containing path

Question

I have an array like

$arr = [
  'foo' => [
    'bar' => [
      1
    ],
    'baz' => [
      1
    ]
  ]
]

And another one

$path = ['foo', 'bar', 0];

I need to modify the value from $arr using $path. I need the solution to be very simple, I tried something like

$arr...$path = 2;
$arr[...$path] = 2;

After the modification $arr should look like

$arr = [
  'foo' => [
    'bar' => [
      2
    ],
    'baz' => [
      1
    ]
  ]
]

But I got errors. I don't always know how many levels the array will have.

its confusing. show the result array you need to recieve from $arr = [ 'foo' => [ 'bar' => [ 1 ] ] ] and $path = ['foo', 'bar']; — M0rtiis
– M0rtiis, Commented Jul 25, 2015 at 8:32

splash58 · Accepted Answer · 2015-07-25 09:00:21Z

4

Your path is incorrect - for $arr[$path] = 2; you need

$path = ['foo', 'bar', 0];

$p = &$arr;
foreach($path as $step) 
   $p = &$p[$step];
echo $p . "\n";
$p = 2;
print_r($arr);

Or with

$path = ['foo', 'bar'];

$p = &$arr;
foreach($path as $step) 
   $p = &$p[$step];
echo $p[0] . "\n";
$p[0] = 2;
print_r($arr);

answered Jul 25, 2015 at 9:00

splash58

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Comments

Alice · Accepted Answer · 2015-07-25 21:01:02Z

1

Try this:

$link =& $arr;
foreach ($path AS $p) 
{
    $link =& $link[$p];
}
$link[0]++;

Alice

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answered Jul 25, 2015 at 8:49

M0rtiis

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JOE LEE · Accepted Answer · 2015-07-25 08:31:38Z

-1

$arr[$path[0]][$path[1]] ='XXX'

answered Jul 25, 2015 at 8:31

JOE LEE

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That is not very helpful.