I have this array and i want to compare each key items with each other and get similars with array_intersect . I wrote this code but it just compare first 2 key items and i want to compare all of key items.
$res_arr = array_shift($m);
foreach($m as $filter){
$arr = array_intersect($res_arr, $filter);
}
If you want the intersection of all the arrays inside the initial array, you need to perform the intersection of the elements with the intersection of the previous elements:
$arr = [
0=>[...],
1=>[...],
2=>[...],
];
$intersection = array_pop($arr);
foreach($arr as $el)
$intersection = array_intersect($arr, $intersection);
print_r($intersection);
Please not that in your example you have 1+ empty array, and so the intersection will be an empty array
Related
I have a multidimensional array in PHP where I need to remove one array based on the value of an item in one of the arrays:
Example Array
array(
"0"=>array("0"=>"joe", "1"=>"2018-07-18 09:00:00"),
"1"=>array("0"=>"tom", "1"=>"2018-07-17 09:00:00"),
"2"=>array("0"=>"joe", "1"=>"2018-07-14 09:00:00")
)
I know that I want to remove the array that contains joe in key 0, but I only want to remove the array that contains joe with the most current date in key1. The following output is what I'm trying to accomplish:
array(
"0"=>array("0"=>"tom", "1"=>"2018-07-17 09:00:00"),
"1"=>array("0"=>"joe", "1"=>"2018-07-14 09:00:00")
)
Is there a simple way to do this in PHP aside from looping through each array?
Here is a non looping method that uses array_intersect and array_column to find the "Joe's" and then deletes the maximum array_key since I first sort the array on dates.
usort($arr, function($a, $b) {
return $a[1] <=> $b[1];
}); // This returns the array sorted by date
// Array_column grabs all the names in the array to a single array.
// Array_intersect matches it to the name "Joe" and returns the names and keys of "Joe"
$joes = array_intersect(array_column($arr, 0), ["joe"]);
// Array_keys grabs the keys from the array as values
// Max finds the maximum value (key)
$current = max(array_keys($joes));
unset($arr[$current]);
var_dump($arr);
https://3v4l.org/mah6K
Edit forgot to add the array_values() if you want to reset the keys in the array.
Just add $arr = array_values($arr); after the unset.
I would go about it like this:
<?php
$foo = array(
"0"=>array("0"=>"joe", "1"=>"2018-07-18 09:00:00"),
"1"=>array("0"=>"tom", "1"=>"2018-07-17 09:00:00"),
"2"=>array("0"=>"joe", "1"=>"2018-07-14 09:00:00")
);
$tmp = [];
foreach($foo as $k => $v) {
if ($v[0] === 'joe') {
$tmp[$v[1]] = $k;
}
}
if (!empty($tmp)) {
sort($tmp); //think that is sane with date format?
unset($foo[reset($tmp)]);
}
var_dump($foo);
Not sure if you don't want to loop on principal or what... I tend to go for readability. Find all occurrences of joe. Sort on date. Remove the most recent by key.
I have an array like this:
array(13,4,7,1,16);
I want to recount the array, but I want to keep the sequence, like this:
array(4,2,3,1,5);
How can I do this?
If you are trying to sort the array, keeping the keys in the same order as the values, the PHP asort() function does that.
If you want to keep the original array but get the keys in sort order, then you can use something like:
$arr = array(13,4,7,1,16);
asort($arr);
$keys = array_keys($arr);
Then $keys has the keys from the original array sorted in the order of the original values, e.g. $keys = array(4,2,3,1,5);
if you want to get the index of the array with reference to the sorted values
Try this
$numbers = array(13,4,7,1,16);
$numberscopy = $numbers;
sort($numberscopy);
$final = array();
//echo array_search(13, $numbers);
for($a=0 ; $a<count($numberscopy );$a++){
$final[] = array_search($numberscopy[$a], $numbers) + 1;
}
var_dump($final);
I have the following two arrays:
$array_one = array('colorZero'=>'black', 'colorOne'=>'red', 'colorTwo'=>'green', 'colorThree'=>'blue', 'colorFour'=>'purple', 'colorFive'=>'golden');
$array_two = array('colorOne', 'colorTwo', 'colorThree');
I want an array from $array_one which only contains the key-value pairs whose keys are members of $array_two (either by making a new array or removing the rest of the elements from $array_one)
How can I do that?
I looked into array_diff and array_intersect, but they compare values with values, and not the values of one array with the keys of the other.
As of PHP 5.1 there is array_intersect_key (manual).
Just flip the second array from key=>value to value=>key with array_flip() and then compare keys.
So to compare OP's arrays, this would do:
$result = array_intersect_key( $array_one , array_flip( $array_two ) );
No need for any looping the arrays at all.
Update
Check out the answer from Michel: https://stackoverflow.com/a/30841097/2879722. It's a better and easier solution.
Original Answer
If I am understanding this correctly:
Returning a new array:
$array_new = [];
foreach($array_two as $key)
{
if(array_key_exists($key, $array_one))
{
$array_new[$key] = $array_one[$key];
}
}
Stripping from $array_one:
foreach($array_one as $key => $val)
{
if(array_search($key, $array_two) === false)
{
unset($array_one[$key]);
}
}
Tell me if it works:
for($i=0;$i<count($array_two);$i++){
if($array_two[$i]==key($array_one)){
$array_final[$array_two[$i]]=$array_one[$array_two[$i]];
next($array_one);
}
}
I have a multidimensional array:
$arr = array(
array('lions', 'tigers', 'bears'), // count = 3
array('dogs', 'cats'), // count = 2
array('horses', 'pigs', 'cattle', 'sheep', 'chickens') // count = 5
);
I want to return the array with the lowest count (I don't need to know the count, just need the array that HAS the lowest count). In this case, array('dogs', 'cats')
Right now I have:
$lowest = null;
foreach($nodePath as $arr)
{
$lowest = count($arr) < count($lowest) || $lowest == null ? $arr : $lowest;
}
This works but I'm wondering if I missed a more contained solution, perhaps using array_map, array_walk or a similar function.
Use array_map() with count as a callback to get the number of elements in each array, min() to get the smallest value. Then, to get the key of the smallest array - use array_flip() to flip the arrays keys and values, and access the $minth index. Now you can use the key to get the array you need:
$counts = array_map('count', $arr);
$min = min($counts);
$key = array_flip($counts)[$min];
$smallest_arr = $arr[$key];
Demo
Map your array to another array with counts of each child array. Get the key of the minimum value in this new array. Smallest array has the key of the minimum value:
$count = array_map('count', $arr);
$min = array_keys($count , min($count))[0];
var_dump($arr[$min]); // Array ( [0] => dogs [1] => cats )
Eval.in
I have 2 arrays, the value will be loaded from database, below is an example:
$arr1 = array(1,2,3);
$arr2 = array(1,2,3,4,5,6,7);
What I want to do is to check if all the values in $arr1 exist in $arr2. The above example should be a TRUE while:
$arr3 = array(1,2,4,5,6,7);
comparing $arr1 with $arr3 will return a FALSE.
Normally I use in_array because I only need to check single value into an array. But in this case, in_array cannot be used. I'd like to see if there is a simple way to do the checking with a minimum looping.
UPDATE for clarification.
First array will be a set that contains unique values. Second array can contain duplicated values. They are both guaranteed an array before processing.
Use array_diff():
$arr1 = array(1,2,3);
$arr2 = array(1,2,3,4,5,6,7);
$arr3 = array_diff($arr1, $arr2);
if (count($arr3) == 0) {
// all of $arr1 is in $arr2
}
You can use array_intersect or array_diff:
$arr1 = array(1,2,3);
$arr2 = array(1,2,3,4,5,6,7);
if ( $arr1 == array_intersect($arr1, $arr2) ) {
// All elements of arr1 are in arr2
}
However, if you don't need to use the result of the intersection (which seems to be your case), it is more space and time efficient to use array_diff:
$arr1 = array(1,2,3);
$arr2 = array(1,2,3,4,5,6,7);
$diff = array_diff($arr1, $arr2);
if ( empty($diff) ) {
// All elements of arr1 are in arr2
}
You can try use the array_diff() function to find the difference between the two arrays, this might help you. I think to clarify you mean, all the values in the first array must be in the second array, but not the other way around.
In my particular case I needed to check if a pair of ids was processed before or not. So simple array_diff() did not work for me.
Instead I generated keys from ids sorted alphabetically and used them with in_array:
<?php
$pairs = array();
// ...
$pair = array($currentId, $id);
sort($pair);
$pair = implode('-', $pair);
if (in_array($pair, $pairs)) {
continue;
}
$pairs[$pair] = $pair;
This is probably not an optimum solution at all but I just needed it for a dirty script to be executed once.