Randomly Unset Element in Multidimensional Array if key-value Exists - php

I have a multidimensional array in PHP taking on the form of the following:
$data = array(
array('spot'=>1,'name'=>'item_1'),
array('spot'=>2,'name'=>'item_2'),
array('spot'=>1,'name'=>'item_3'),
);
If more than one array element contains a duplicate for the 'spot' number I would want to randomly select a single one and unset all other elements with the same 'spot' value. What would be the most efficient way to execute this? The resulting array would look like:
$data = array(
array('spot'=>2,'name'=>'item_2'),
array('spot'=>1,'name'=>'item_3'),
);

Store the values of spot in another array. Using array_count_values check which values occur more than once. Find the keys for those values. Select a random key. Delete all keys except the selected key from the original array. Here is the code:
$data = array(
array('spot'=>1,'name'=>'item_1'),
array('spot'=>2,'name'=>'item_2'),
array('spot'=>1,'name'=>'item_3'),
);
$arr = array();
foreach($data as $val){
$arr[] = $val['spot'];
}
foreach(array_count_values($arr) as $x => $y){
if($y == 1) continue;
$keys = array_keys($arr, $x);
$rand = $keys[array_rand($keys)];
foreach($keys as $key){
if($key == $rand) continue;
unset($data[$key]);
}
}

Related

Replace array value with more than one values

I have an array like this,
$array = array(
1,2,3,'4>12','13.1','13.2','14>30'
);
I want to find any value with an ">" and replace it with a range().
The result I want is,
array(
1,2,3,4,5,6,7,8,9,10,11,12, '13.1', '13.2', 14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30
);
My understanding:
if any element of $array has '>' in it,
$separate = explode(">", $that_element);
$range_array = range($separate[0], $separate[1]); //makes an array of 4 to 12.
Now somehow replace '4>12' of with $range_array and get a result like above example.
May be I can find which element has '>' in it using foreach() and rebuild $array again using array_push() and multi level foreach. Looking for a more elegant solution.
You can even do it in a one-liner like this:
$array = array(1,2,3,'4>12','13.1','13.2','14>30');
print_r(array_reduce(
$array,
function($a,$c){return array_merge($a,#range(...array_slice(explode(">","$c>$c"),0,2)));},
[]
));
I avoid any if clause by using range() on the array_slice() array I get from exploding "$c>$c" (this will always at least give me a two-element array).
You can find a little demo here: https://rextester.com/DXPTD44420
Edit:
OK, if the array can also contain non-numeric values the strategy needs to be modified: Now I will check for the existence of the separator sign > and will then either merge some cells created by a range() call or simply put the non-numeric element into an array and merge that with the original array:
$array = array(1,2,3,'4>12','13.1','64+2','14>30');
print_r(array_reduce(
$array,
function($a,$c){return array_merge($a,strpos($c,'>')>0?range(...explode(">",$c)):[$c]);},
[]
));
See the updated demo here: https://rextester.com/BWBYF59990
It's easy to create an empty array and fill it while loop a source
$array = array(
1,2,3,'4>12','13.1','13.2','14>30'
);
$res = [];
foreach($array as $x) {
$separate = explode(">", $x);
if(count($separate) !== 2) {
// No char '<' in the string or more than 1
$res[] = $x;
}
else {
$res = array_merge($res, range($separate[0], $separate[1]));
}
}
print_r($res);
range function will help you with this:
$array = array(
1,2,3,'4>12','13.1','13.2','14>30'
);
$newArray = [];
foreach ($array as $item) {
if (strpos($item, '>') !== false) {
$newArray = array_merge($newArray, range(...explode('>', $item)));
} else {
$newArray[] = $item;
}
}
print_r($newArray);

PHP create 1 array of 4 arrays ordered by index

I have 4 arrays, each one holds another column of a table, I would like to create one array with the data ordered per array[$i]. All arrays have the same number of values: $namesArr, $folderArr, $updatedAt, $valuesArr .
I would like my new array to be contain:
$namesArr[0], $folderArr[0], $updatedAt[0], $valuesArr[0],
$namesArr[1], $folderArr[1], $updatedAt[1], $valuesArr[1],
$namesArr[2], $folderArr[2], $updatedAt[2], $valuesArr[2],
...
I guess the solution is pretty simple, but I got stuck :(
Can anyone help?
I would do something like:
$arr = array_map(function () { return func_get_args(); },$namesArr, $folderArr, $updatedAt, $valuesArr);
You can use foreach loop to merge 4 arrays:
foreach ($namesArr as $key => $value) {
$arr[$key][] = $value;
$arr[$key][] = $folderArr[$key];
$arr[$key][] = $updatedAt[$key];
$arr[$key][] = $valuesArr[$key];
}
Thus $arr will be the merged array
<?php
$newArr = array();
for ($i = 0; $i < count($namesArr); $i++)
{
$newArr[$i][0] = $namesArr[$i];
$newArr[$i][1] = $folderArr[$i];
$newArr[$i][2] = $updatedAt[$i];
$newArr[$i][3] = $valuesArr[$i];
}
?>
Explanation
What this will do is iterate depending on how many elements there are in $namesArr.
I utilised a multidimensional array here so that the first set of square brackets is effectively the "row" in a table, and the second set of square brackets are the "column" of a table.
do the following way:
while($db->query($sql)){
$namesArr[] =$db->f('names');
$folderArr[]=$db->f('folder');
$updatedAt[]=$db->f('updated');
$valuesArr[]=$db->f('values');
}

Remove all elements in an array after the first instance of an element that matches same alphabetic (ONLY) value

I need to remove all elements in the array that comes after the FIRST instance of an element that matches same string value before the dot. ie, not taking into consideration any values after the .
from
$array = ("ItemNew1.1", "Item2.0", "Item3Test.0", "Item2.2", "Item4.4", "Item2.5")
to
$array = ("ItemNew1.1", "Item2.0", "Item3Test.0", "Item4.4")
The code below creates a temp array to hold the values that are already in the array, it runs a foreach on the original array and if the value is not in the temporary array, it inserts it into a new array
$tempArray = array();
$newArray = array();
foreach($array as $value) {
list($item, ) = explode(".", $value);
$int = filter_var($item, FILTER_SANITIZE_NUMBER_INT);
if(!in_array($int, $tempArray)) {
$newArray[] = $value;
$tempArray[] = $int;
}
}
Now, $newArray is the array that you want.
DEMO

Display array_key from PHP array?

Here I am Having an Issue:
I have two arrays like the following:
$array1 = array('1','2','1','3','1');
$array2 = array('1','2','3'); // Unique $array1 values
with array2 values i need all keys of an array1
Expected Output Is:
1 => 0,2,4
2 => 1
3 => 3
here it indicates array2 value =>array1 keys
Just use a loop:
$result = array();
foreach ($array1 as $index => $value) {
$result[$value][] = $index;
}
If you pass array_keys a 2nd parameter, it'll give you all the keys with that value.
So, just loop through $array2 and get the keys from $array1.
$result = array();
foreach($array2 as $val){
$result[$val] = array_keys($array1, $val);
}
The following code will do the job. It will create a result array in which the attribute val will contain the value that is searched in array and keys attribute will be an array that contains the found keys. Based on your values following is an example:
$array1 =array('1','2','1','3','1');
$array2 =array('1','2','3');
$results = array();
foreach ($array2 as $key2=>$val2) {
$result = array();
foreach ($array1 as $key1=>$val1 ) {
if ($val2 == $val1) {
array_push($result,$key1);
}
}
array_push($results,array("val"=>$val2,keys=>$result ));
}
echo json_encode($results);
The result will be:
[{"val":"1","keys":[0,2,4]},
{"val":"2","keys":[1]},
{"val":"3","keys":[3]}]

PHP - Automatically creating a multi-dimensional array

So here's the input:
$in['a--b--c--d'] = 'value';
And the desired output:
$out['a']['b']['c']['d'] = 'value';
Any ideas? I've tried the following code without any luck...
$in['a--b--c--d'] = 'value';
// $str = "a']['b']['c']['d";
$str = implode("']['", explode('--', key($in)));
${"out['$str']"} = 'value';
This seems like a prime candidate for recursion.
The basic approach goes something like:
create an array of keys
create an array for each key
when there are no more keys, return the value (instead of an array)
The recursion below does precisely this, during each call a new array is created, the first key in the list is assigned as the key for a new value. During the next step, if there are keys left, the procedure repeats, but when no keys are left, we simply return the value.
$keys = explode('--', key($in));
function arr_to_keys($keys, $val){
if(count($keys) == 0){
return $val;
}
return array($keys[0] => arr_to_keys(array_slice($keys,1), $val));
}
$out = arr_to_keys($keys, $in[key($in)]);
For your example the code above would evaluate as something equivalent to this (but will work for the general case of any number of -- separated items):
$out = array($keys[0] => array($keys[1] => array($keys[2] => array($keys[3] => 'value'))));
Or in more definitive terms it constructs the following:
$out = array('a' => array('b' => array('c' => array('d' => 'value'))));
Which allows you to access each sub-array through the indexes you wanted.
$temp = &$out = array();
$keys = explode('--', 'a--b--c--d');
foreach ($keys as $key) {
$temp[$key] = array();
$temp = &$temp[$key];
}
$temp = 'value';
echo $out['a']['b']['c']['d']; // this will print 'value'
In the code above I create an array for each key and use $temp to reference the last created array. When I run out of keys, I replace the last array with the actual value.
Note that $temp is a REFERENCE to the last created, most nested array.

Categories