PHP array key exists from string - php

Question

I have an array:
<?php
$array = [
'fruits' => [
'apple' => 'value',
'orange' => 'value'
],
'vegetables' => [
'onion' => 'value',
'carrot' => 'value'
];
I also have a string:
$string = 'fruits[orange]';
Is there any way to check if the - array key specified in the string - exists in the array?
For example:
<?php
if(array_key_exists($string, $array))
{
echo 'Orange exists';
}

Answer 1

Try this one. Here we are using foreach and isset function.
Note: This solution will also work for more deeper levels Ex: fruits[orange][x][y]
Try this code snippet here
<?php
ini_set('display_errors', 1);
$array = [
'fruits' => [
'apple' => 'value',
'orange' => 'value'
],
'vegetables' => [
'onion' => 'value',
'carrot' => 'value'
]
];
$string = 'fruits[orange]';
$keys=preg_split("/\[|\]/", $string, -1, PREG_SPLIT_NO_EMPTY);
echo nestedIsset($array,$keys);
function nestedIsset($array,$keys)
{
foreach($keys as $key)
{
if(array_key_exists($key,$array))://checking for a key
$array=$array[$key];
else:
return false;//returning false if any of the key is not set
endif;
}
return true;//returning true as all are set.
}

Answer 2

It would be a lot easier to check the other way around. As in check if the key is in the string. Since keys are unique, there's no way you have duplicates.
$array = [
'fruits' => [
'apple' => 'value',
'orange' => 'value'
],
'vegetables' => [
'onion' => 'value',
'carrot' => 'value'
]
];
$string = 'fruits[orange]';
$keys = array_keys($array['fruits']);
foreach($keys as $fruit) {
if(false !== stripos($string, $fruit)) {
return true;
}
}
While this solution is not necessarily ideal, the problem to begin with isn't exactly common.

Answer 3

You can walk recursively:
$array = [
'fruits' => [
'apple' => 'value',
'orange' => 'value'
],
'vegetables' => [
'onion' => 'value',
'carrot' => 'value'
]
];
$exists = false;
$search = "orange";
array_walk_recursive($array, function ($val, $key) use (&$exists,$search) {
if ($search === $key) { $exists = true; }
});
echo ($exists?"Exists":"Doesn't exist");
Prints:
Exists
Example: http://sandbox.onlinephpfunctions.com/code/a3ffe7df25037476979f4b988c2f36f35742c217

Answer 4

Instead of using regex or strpos like the other answers, you could also simply split your $string on [ and resolve the keys one by one until there's only one key left. Then use that last key in combination with array_key_exists() to check for your item.
This should work for any amount of dimensions (eg fruit[apple][value][1]).
Example:
<?php
$arr = [
'fruits' => [
'orange' => 'value'
]
];
// Resolve keys by splitting on '[' and removing ']' from the results
$keys = 'fruits[orange]';
$keys = explode("[", $keys);
$keys = array_map(function($s) {
return str_replace("]", "", $s);
}, $keys);
// Resolve item.
// Stop before the last key.
$item = $arr;
for($i = 0; $i < count($keys) - 1; $i++) {
$item = $item[$keys[$i]];
}
// Check if the last remaining key exists.
if(array_key_exists($keys[count($keys)-1], $item)) {
// do things
}

Answer 5

You can explode and check the indices of the array.
$array = array(
'fruits' => [
'apple' => 'value',
'orange' => 'value'
],
'vegetables' => [
'onion' => 'value',
'carrot' => 'value'
]);
$string = 'fruits[orange]';
$indexes = (preg_split( "/(\[|\])/", $string));
$first_index= $indexes[0];
$seconnd_index= $indexes[1];
if(isset($array[$first_index][$seconnd_index]))
{
echo "exist";
}
else
{
echo "not exist";
}
DEMO