I was wondering if it was possible to determine what position a key in an array is in relation to another key. I have a large multidimensional array and I need perform Function A when the key [E14_21] comes before [E14_20] and I need to perform a different Function B if not...
//perform Function A if:
[E14_20_0] => Array
(
[E14_21] => 3235
[E14_20] => 96
)
//Perform Function B if:
[E14_20_0] => Array
(
[E14_20] => 96
[E14_21] => 3235
)
You can do something like:
$keys = array_keys($E14_20_0);
if(array_search("E14_21", $keys) < array_search("E14_20", $keys)) {
// function A
} else {
// function B
}
You will of course need to add some sanity checks to make sure both keys exist in the array, etc.
It seems you might do this:
reset($E14_20_0);
first = each($E14_20_0);
second = each($E14_20_0);
if(first['key'] > second['key'])
{
//do something
}
This is very specific to your example, but it might help you get started.
reset() will reset the array pointer to the "first" element. each() returns the key and value of the array based on the pointer and advances the pointer. Then you can compare keys and perform your logic.
Related
function values($id,$col)
{
$vals = [1=>['name'=>'Lifting Heavy Boxes']];
return $vals[$id][$col];
}
$complete = [1=>["id"=>"2","sid"=>"35","material_completed"=>"1","date"=>"2017-12-18"]];
$form = 'my_form';
array_walk($complete, function(&$d,$k) use($form) {
$k = values($k, 'name').' ['.date('m/d/y',strtotime($d['date'])).'] ('.$form.')';
echo 'in walk '.$k."\n";
});
print_r($complete);
the echo outputs:
in walk Lifting Heavy Boxes [12/18/17] (my_form)
the print_r outputs:
Array
(
[1] => Array
(
[id] => 2
[sid] => 35
[material_completed] => 1
[date] => 2017-12-18
)
)
I have another array walk that is very similar that is doing just fine. The only difference I can perceive between them is in the one that's working, the value $d is already a string before it goes through the walk, whereas in the one that's not working, $d is an array that is converted to a string inside the walk (successfully, but ultimately unsuccessfully).
Something I'm missing?
And here's the fixed version:
array_walk($complete, function(&$d,$k) use($form) {
$d = values($k, 'name').' ['.date('m/d/y',strtotime($d['date'])).'] ('.$form.')';
});
That's what I was trying to do anyway. I wasn't trying to change the key. I was under the mistaken impression that to change the value you had to set the key to the new value.
You cannot change the key of the array inside the callback of array_walk():
Only the values of the array may potentially be changed; its structure cannot be altered, i.e., the programmer cannot add, unset or reorder elements. If the callback does not respect this requirement, the behavior of this function is undefined, and unpredictable.
This is also mentioned in the first comment:
It's worth nothing that array_walk can not be used to change keys in the array.
The function may be defined as (&$value, $key) but not (&$value, &$key).
Even though PHP does not complain/warn, it does not modify the key.
I am trying to make a simple class that I can use to check if a value exists within an array. There is a session that contains multiple tool values. I am trying to pass the toolID to this function as well as a key and see if that value exists.
Session Data:
Array
(
[keyring] => Array
(
[tool] => Array
(
[toolID] => 1859
[keys] => Array
(
[0] => 49
[1] => 96
)
)
)
)
class Keyring
{
public function checkKey($key, $toolID){
$keyring = $_SESSION['keyring'];
if(isset($keyring)){
foreach($keyring['tool'] as $k => $v) {
if($k == 'toolID' && $v == $toolID){
if (in_array($key, $k->keys)){
return true;
}
}
}
}
return false;
}
}
$keyring = new Keyring();
print_r($keyring->checkKey(49, 1859));
In this example, I am trying to see if key 49 exists in the session for tool 1859.
I am getting the following error : Warning: in_array() expects parameter 2 to be array, null given in.
Is there a better approach for this? All I am looking for is a true/false as to whether that key exists in the keys array for the specified tool.
For my code to work for you may need to change your array a bit or change the code a bit, but rather then looping through a bunch of keys trying to find the right one we are just looking for the keys in the array if they are not set, then return false, or if we find keyring - tools - $tool_id - key_{$key_id} we are just going to return that value, if key_49 = false the function returns false. This should be a tad bit quicker to run on the server for you.
function has_keyring($tool_id, $key_id)
{
//Just to keep the code tidy let's store the tools key in $tool variable
$tool = $_SESSION['keyring']['tools'];
if(isset($tool[$tool_id]) && isset($tool[$tool_id]["key_{$key_id}"]))
return $tool[$tool_id]["key_{$key_id}"];
return false;
}
Here is the function I wrote to flatten the multidimensional PHP array:
function flattenArray(array $array) {
if (! is_array($array)) {
throw new Exception ("Please specify an array.");
}
$resultArray = [];
$arrayObject = new RecursiveArrayIterator($array);
foreach(new RecursiveIteratorIterator($arrayObject) as $key => $value) {
$resultArray[$key] = $value;
}
return $resultArray;
}
And using it:
$arr = [
["sitepoint", "phpmaster"],
["buildmobile", "rubysource"],
["designfestival", "cloudspring"],
"not an array"
];
print_r(flattenArray($arr));
Result:
Array
(
[0] => designfestival
[1] => cloudspring
[3] => not an array
)
However, I was expecting:
0: sitepoint
1: phpmaster
2: buildmobile
3: rubysource
4: designfestival
5: cloudspring
6: not an array
But it is re-generating indexes as in:
0: sitepoint
1: phpmaster
0: buildmobile
1: rubysource
0: designfestival
1: cloudspring
3: not an array
So how do I modify function to get all elements of the array not just three:
Array
(
[0] => designfestival
[1] => cloudspring
[3] => not an array
)
Thanks for the help
if (!is_array($array)) is superfluous, since you have the array type hint in the function signature and PHP will enforce that.
You are overwriting the keys. Those elements all have the same keys in their respective subarray. Since it's not an associative array, you don't need to preserve the keys. Instead of
$resultArray[$key] = $value;
just do
$resultArray[] = $value;
I too hit this limitation with RecursiveIteratorIterator.
At first I had been using this concise, one-line array flattener wherever needed:
$outputs = iterator_to_array(new \RecursiveIteratorIterator(new \RecursiveArrayIterator([$inputs])), FALSE);
similar to your longer function above.
All was great: I was able to "normalize" my data structure into a 1D array, no matter if the incoming $inputs parameter came into my Symfony2 Controller as a single String/float value, 1D or 2+D multidimensional array. (I was writing a callback from AJAX that is to respond with JSON-formatted tables for an interactive Highcharts.com chart to be able to render, in my financial app.)
However, it refused to draw because in the final step, each data cell was in the form
0 => float 100.662
even though I had taken care that my $inputs creature only contained cells in the form:
'2002-04-30' => float 100.662
So basically the above array-flattening line had killed the keys (DateStamp).
Fed up with studying RecursiveIteratorIterator, I just broke down and came up with my own array_flatten that preserves keys, if any:
static public function array_flatten($inObj)
{
$outObj = []; $inObj=[$inObj];
array_walk_recursive($inObj, function ($incell, $inkey) use (&$outObj)
{
$outObj[$inkey] = $incell;
} );
return $outObj;
}
Note that you are responsible for ensuring that the keys in $inObj are globally unique (and either string or int type), otherwise, I don't know how my function behaves. Probably overwrites the value using the same key name?
Finding the right title for this was next to impossible.
Imagine this scenario:
We have an array that contains certain product tags. The key is each tag's unique id and the value is its label:
Available Tags
Array (
[3] => Sweet
[4] => Sour
[5] => Bitter
[6] => Winter
[7] => Organic
)
We have another array which contains the tags that have been selected. The selection has a specific order which is defined by the key, while the value represents the id (of the actual tag we see in array #1).
Selected Tags in Specific Order
Array (
[10] => 4
[20] => 3
[30] => 7
)
My theoretical Approach
Certainly i could go about foreach-ing through the second array, collecting the appropriate values (that correspond to the first array's entries) in a new array. Then i could iterate over the first array and add all the values (to the new array) which are not yet present in the new array.
Quite honestly - that doesn't feel very professional. Unfortunately, i have no idea how to do this better.
Question
How can i neatly sort the first array (Available Tags) by using the chronology defined by the second array (Selected Tags)?
Note
I want to end up with all items from the first array. Not just the ones that are listed in the second one.
In case someone's curious: this is for multiple-selects which are sortable. Items which have been selected are sortable and must therefore appear in the right order. The other items order doesn't matter. My server-side data handler class gives me these two arrays as described, so that's what i got to work with.
Here's a solution that uses uksort(). Elements of the $tags array that are not present in the $order array are sorted to the end, and the relative order between them is undefined.
function my_sort($a, $b) {
global $order;
if(in_array($a, $order)) {
if(in_array($b, $order)) {
// Both $a and $b have an order
return array_search($a, $order) - array_search($b, $order);
}
else {
// Only $a has an order, so it goes before $b
return -1;
}
}
else if(in_array($b, $order)) {
// Only $b has an order, so it goes before $a
return 1;
}
else {
// Neither $a or $b has an order, so we don't care how they're sorted
return 0;
}
}
uksort($tags, 'my_sort');
I think you can just loop in your second array and build a new one using keys
$new = array();
foreach($array2 as $key => $val)
{
$new_array[] = $array1[$val];
}
Now the selected items are ordered in your $new_array
Sample
I am using Cassandra and I have saved some byte representations as ID. Everything is working fine, however that data (id) is no good for output.
$users = $db->get('1');
echo '<pre>';
print_r($users);
die();
Outputs
Array
(
[��� X��W��c_ ] => Array
(
[id] => ��� X��W��c_
[name] => steve
[surname] => moss
)
[�*B�X��y�~p��~] => Array
(
[id] => �*B�X��y�~p��~
[name] => john
[surname] => doe
)
)
As you can see ID's are some wierd characters, it's because they are byte representations in database. They actually look like \xf5*B\xa0X\x00\x11\xe1\x99y\xbf~p\xbc\xd1~.
In PHPCASSA there is function CassandraUtil::import(); to which I can pass these bytes and it will return guid. It works fine, but I want my array to automatically converted from bytes to guids.
Only option I find is looping through every item in array and assigning new value to it. Somehow I think that it is not the best approach. Is there any other ways to do this?
TL;DR
Have array with bytes like above, need to use CassandraUtil::import(); on array keys and id's to get readable id's. What is the most effective way of doing so.
UPDATE
Sorry, only saw the top level array key, I think you would have to run the function below as well as another one after:
function cassImportWalkRecur(&$item, $key)
{
if ($key == 'id')
$item = CassandraUtil::import();
}
$array = array_walk_recursive($array, 'cassImportWalkRecur');
That should apply it to the ID fields. If you need to check the data first, there maybe a way to detect the encoding, but I am not sure how to do that.
You should be able to create a function and use array_walk to traverse the array and update the keys. Something like:
function cassImportWalk($item, &$key)
{
$key = CassandraUtil::import();
}
$array = array_walk($array, 'cassImportWalk');
Untested (also you may have to change the CassandraUtil usage), but should work.
Unless I am misunderstanding the question this can be done simply and cleanly like so:
$users = $db->get('1');
$keys = array_keys($users);
$readableKeys = array_map("CassandraUtil::import",$keys);
foreach($users as $currentKey => $subArray) {
$readableKey = array_shift($readableKeys);
$subArray['id'] = $readableKey;
$users[$readableKey] = $subArray;
unset($users[$currentKey]);
}
Would array_flip() all keys and values, then array_walk() and apply my function, before doing a final array_flip().