I have a string like this:
$string = 'one/two/three/four';
which I turn it into a array:
$keys = explode('/', $string);
This array can have any number of elements, like 1, 2, 5 etc.
How can I assign a certain value to a multidimensional array, but use the $keys I created above to identify the position where to insert?
Like:
$arr['one']['two']['three']['four'] = 'value';
Sorry if the question is confusing, but I don't know how to explain it better
This is kind of non-trivial because you want to nest, but it should go something like:
function insert_using_keys($arr, $keys, $value){
// we're modifying a copy of $arr, but here
// we obtain a reference to it. we move the
// reference in order to set the values.
$a = &$arr;
while( count($keys) > 0 ){
// get next first key
$k = array_shift($keys);
// if $a isn't an array already, make it one
if(!is_array($a)){
$a = array();
}
// move the reference deeper
$a = &$a[$k];
}
$a = $value;
// return a copy of $arr with the value set
return $arr;
}
$string = 'one/two/three/four';
$keys = explode('/', $string);
$arr = array(); // some big array with lots of dimensions
$ref = &$arr;
while ($key = array_shift($keys)) {
$ref = &$ref[$key];
}
$ref = 'value';
What this is doing:
$ref, to keep track of a reference to the current dimension of $arr.$keys one at a time, referencing the $key element of the current reference.
$keys contains 0 or NULL?
$arr is not an array, along with a handful of other cases. Bullet-proof error-checking is not a prerequisite for a correct answer.You'll need to first make sure the key's exist, then assign the value. Something like this should work (untested):
function addValueByNestedKey(&$array, $keys, $value) {
$branch = &$array;
$key = array_shift($keys);
// add keys, maintaining reference to latest branch:
while(count($keys)) {
$key = array_pop($keys);
if(!array_key_exists($key, $branch) {
$branch[$key] = array();
}
$branch = &$branch[$key];
}
$branch[$key] = $value;
}
// usage:
$arr = array();
$keys = explode('/', 'one/two/three/four');
addValueByNestedKey($arr, $keys, 'value');
it's corny but:
function setValueByArrayKeys($array_keys, &$multi, $value) {
$m = &$multi
foreach ($array_keys as $k){
$m = &$m[$k];
}
$m = $value;
}
$multi = $multi[$k] creates a copy, it's not a reference, so you're not actually modifying anything when you do $multi = $value, except the final array.
$multi as a parameter generates a copy, the first reference you assign to $m is to the copy, not the original. You can (a) make $multi a reference in the parameter list or (b) return $multi. $arr['one']['two']['three']['four'] = 'value';
$string = 'one/two/three/four';
$ExpCheck = explode("/", $string);
$CheckVal = $arr;
foreach($ExpCheck AS $eVal){
$CheckVal = $CheckVal[$eVal]??false;
if (!$CheckVal)
break;
}
if ($CheckVal) {
$val =$CheckVal;
}
this will give u your value in array.
