php remove duplicates based on first value of multidimensional array - php

Given
[0] => Array
(
[0] => ask.com
[1] => 2320476
)
[1] => Array
(
[0] => amazon.com
[1] => 1834593
)
[2] => Array
(
[0] => ask.com
[1] => 1127456
)
I need to remove duplicate values solely based on first value, regardless of what any other subsequent values may be. Notice [0][1] differs from [2][1] yet I consider this as a duplicate because there are two matching first values. The other data is irrelevant and shouldn't be considered in comparison.

Try this, assuming that $mainArray is the array you have.
$outputArray = array(); // The results will be loaded into this array.
$keysArray = array(); // The list of keys will be added here.
foreach ($mainArray as $innerArray) { // Iterate through your array.
if (!in_array($innerArray[0], $keysArray)) { // Check to see if this is a key that's already been used before.
$keysArray[] = $innerArray[0]; // If the key hasn't been used before, add it into the list of keys.
$outputArray[] = $innerArray; // Add the inner array into the output.
}
}
print_r($outputArray);

Related

Through an array with other array in php

I have a question for you, I need to through an array with other arrays in php but i through only the last array, my array is:
Array
(
[0] => Array
(
[syn_id] => 17070
[syn_label] => fd+dfd
)
[1] => Array
(
[syn_id] => 17068
[syn_label] => fds+dsfds
)
[2] => Array
(
[syn_id] => 17069
[syn_label] => klk+stw
)
)
My php:
$a_ddata = json_decode(method(), true);
foreach ($a_ddata as $a_data)
{
$a_data['syn_label'] = urldecode(utf8_decode($a_data['syn_label']));
}
With this code I through only the last array [2], but how to through array?please help me
I need to get the array:
Array
(
[0] => Array
(
[syn_id] => 17070
[syn_label] => fd dfd
)
[1] => Array
(
[syn_id] => 17068
[syn_label] => fds dsfds
)
[2] => Array
(
[syn_id] => 17069
[syn_label] => klk stw
)
)
$a_ddata = json_decode(method(), true); $i=0;
foreach ($a_ddata as $a_data)
{
$a_data_f[$i]['syn_id'] = $a_data['syn_id'];
$a_data_f[$i]['syn_label'] = urldecode(utf8_decode($a_data['syn_label']));
$i++;
}
This should be your answer..
When you iterate through something using foreach, by default PHP makes a copy of each element for you to use within the loop. So in your code,
$a_ddata = json_decode(method(), true);
foreach ($a_ddata as $a_data)
{
// $a_data is a separate copy of one of the child arrays in $a_ddata
// this next line will modify the copy
$a_data['syn_label'] = urldecode(utf8_decode($a_data['syn_label']));
// but at the end of the loop the copy is discarded and replaced with a new one
}
Fortunately the manual page for foreach gives us a way to override this behavior with the reference operator &. If you place it between the as keyword and your loop variable, you're able to update the source array within your loop.
$a_ddata = json_decode(method(), true);
foreach ($a_ddata as &$a_data)
{
// $a_data is now a reference to one of the elements to $a_ddata
// so, this next line will update $a_ddata's individual records
$a_data['syn_label'] = urldecode(utf8_decode($a_data['syn_label']));
}
// and you should now have the result you want in $a_ddata
This should help:
$a_data['syn_label'][] = urldecode(utf8_decode($a_data['syn_label']));
For each iteration you are only replacing $a_data['syn_label']. By adding [] you are making it a multi dimension array which increments for every iteration.

Two PHP arrays, unset positions that are only present in one array

I have two arrays (in PHP):
ArrayA
(
[0] => 9
[1] => 1
[2] => 2
[3] => 7
)
ArrayB
(
[0] => 1
[1] => 1
[3] => 8
)
I want to make two new arrays, where I have only the elements declared in both of the arrays, like the following:
ArrayA
(
[0] => 9
[1] => 1
[3] => 7
)
ArrayB
(
[0] => 1
[1] => 1
[3] => 8
)
In this example ArrayA[2] doesn't exist, so ArrayB[2] has been unset.
I wrote this for loop:
for ($i = 0, $i = 99999, $i++){
if (isset($ArrayA[$i]) AND isset($ArrayB[$i]) == FALSE)
{
unset($ArrayA[$i],$ArrayB[$i]);
}
}
But it's not great because it tries every index between 0 and a very big number (99999 in this case). How can I improve my code?
The function you're looking for is array_intersect_key:
array_intersect_key() returns an array containing all the entries of array1 which have keys that are present in all the arguments.
Since you want both arrays, you'll have to run it twice, with the parameters in opposite orders, as it only keeps keys from the first array. An example:
$arrayA_filtered = array_intersect_key($arrayA, $arrayB);
$arrayB_filtered = array_intersect_key($arrayB, $arrayA);
Also, although a for loop wasn't ideal in this case, in other cases where you find yourself needing to loop through sparse array (one where not every number is set), you can use a foreach loop:
foreach($array as $key => $value) {
//Do stuff
}
One very important thing to note about PHP arrays is that they are associative. You can't simply use a for loop, as the indices are not necessarily a range of integers. Consider what would happen if you applied this algorithm twice! You'd get out of bounds errors as $arrayA[2] and $arrayB[2] no longer exist!
I would iterate through the arrays using nested foreach statements. I.e.
$outputA = array();
$outputB = array();
foreach ($arrayA as $keyA => $itemA) {
foreach ($arrayB as $keyB => $itemB) {
if ($keyA == $keyB) {
$outputA[$keyA] = $itemA;
$outputB[$keyB] = $itemB;
}
}
This should give you two arrays, $outputA and $outputB, which look just like $arrayA and $arrayB, except they only include key=>value pairs if the key was present in both original arrays.
foreach($arrayA as $k=>$a)
if (!isset($arrayB[$k]))
unset($arrayA[$k];
Take a look to php : array_diff
http://docs.php.net/manual/fr/function.array-diff.php

PHP - Comparing two multidimensional arrays

I have two arrays with data in them and I need to compare the two and create one final array.. here is my situation:
// grab a list of the folders
$folders = glob("../*",GLOB_ONLYDIR);
// create empty array's which will contain our data
$projects_data = array();
$folders_array = array();
// list the contents of the config file
$data = json_decode(file_get_contents('.my-config'), true);
// loop through our data file
foreach($data['web_app']['projects'] as $project) :
// update our projects data array
$projects_data[] = $project;
endforeach;
// loop through each folder on our localhost
foreach($folders as $folder) :
// update our folders array
$folders_array[] = array(
'folder' => basename($folder),
'last_modified' => filemtime($folder),
'dir_size' => dirsize($folder)
);
endforeach;
so I have two arrays.. like so:
$projects_data array
Array
(
[0] => Array
(
[folder] => GitHub Clones
[last_modified] => 1379974689
[dir_size] => 6148
)
[1] => Array
(
[folder] => MagentoPlayground
[last_modified] => 1380336582
[dir_size] => 82340978
)
[2] => Array
(
[folder] => Projects
[last_modified] => 1380581312
[dir_size] => 5954
)
)
$folders_array array
Array
(
[0] => Array
(
[folder] => MagentoPlayground
[last_modified] => 1380336582
[dir_size] => 82340978
)
[1] => Array
(
[folder] => Projects
[last_modified] => 1380581312
[dir_size] => 5933
)
[2] => Array
(
[folder] => old
[last_modified] => 1371064970
[dir_size] => 63385844
)
)
I need to compare these two arrays.. If there is one that exists in the top array and does not exist in the second array (Github Clones) then I need to remove it. If there is one that exist in the bottom array that does not exist in the top array (old) then I need to add it. I guess I will need a third array with the new data but I'm not sure how to structure this.
Also, if there are two entries in both arrays (MagentoPlayground) I need the new array to use the data from the bottom array. The bottom array will have the most up to date last_modified stamp and directory size.
Thanks for any help.
I'd compare using the rules you've just mentioned:
Exists in A but not in B -> remove
Exists in B but not in A -> add
...and create a third and final array. Due to the first rule, you may as well loop through array B as comparison which will solve that one.
<?php
// multidimensional array key search (one deep)
function m_array_key_exists($key, $array) {
foreach($array as $subkey => $subvalue) {
if($subkey === $key)
return true;
if(is_array($subvalue)){
if(array_key_exists($key, subvalue))
return true;
}
}
return false;
}
?>
Seems from those two rules alone that you may as well just take your second array, because if it exists in both arrays it can stay, if it doesn't exist in B you are going to remove it, but it's not there anyway, and if it exists in B but not A you add it, but it's already there...
Use m_array_key_exists as above to check one level deeper than array_key_exists() whether an array key exists in arrays like you've shown. If your rules aren't as simple as I've thought they are, it sounds to me like you want to loop through your second array, check for array keys, apply your special rules and add the result to the third array.

PHP - change index of parent in multi-dimensional array to child array value where key = string

I've got an multi-dimensional array at the moment and want to remove the second-level of arrays and have the value of that second level as the new index value on the parent array. My current array is:
Array ( [0] => Array ( [connectee] => 1 ) [1] => Array ( [connectee] => 6 ) )
And want from that:
Array ( [0] => 1, [1] => 6 )
I was poking around the usort function but couldn't get it to work (where $current_connections is my array as above:
function cmp($a, $b) {
return strcmp($a["connectee"], $b["connectee"]);
}
$current_connections = usort($current_connections, "cmp");
The key doesn't need to be maintained (should be destroyed in the process).
foreach ($array as &$value) {
$value = $value['connectee'];
}
Note: Please note that the question statement is very confusing and contradicting, but this answer is based upon your statement for expected output
Array ( [0] => 1, [1] => 6 )
You could do
<?php
$values=array();
$values[0]=array("connectee"=>1);
$values[1]=array("connectee"=>6);
foreach($values as $index=>$value)
{
$values[$index]=$value["connectee"];
}
print_r($values);
?>

checking to see if a vaule is in a particular key of an array

I'm new to working with arrays so I need some help. With getting just one vaule from an array. I have an original array that looks like this:
$array1= Array(
[0] => 1_31
[1] => 1_65
[2] => 29_885...)
What I'm trying to do is seach for and return just the value after the underscore. I've figured out how to get that data into a second array and return the vaules as a new array.
foreach($array1 as $key => $value){
$id = explode('_',$value);
}
which gives me:
Array ( [0] => 1 [1] => 31 )
Array ( [0] => 1 [1] => 65 )
Array ( [0] => 29 [1] => 885 )
I can also get a list of the id's or part after the underscore by using $id[1] I'm just not sure if this is the best way and if it is how to do a search. I've tried using in_array() but that searches the whole array and I couldn't make it just search one key of the array.
Any help would be great.
If the part after underscore is unique, make it a key for new array:
$newArray = array();
foreach($array1 as $key => $value){
list($v,$k) = explode('_',$value);
$newArray[$k] = $v;
}
So you can check for key existence with isset($newArray[$mykey]), which will be more efficient.
You can use preg_grep() to grep an array:
$array1= array("1_31", "1_65", "29_885");
$num = 65;
print_r(preg_grep("/^\d+_$num$/", $array1));
Outputs:
Array
(
[1] => 1_65
)
See http://ideone.com/3Fgr8
I would say you're doing it just about as well as anyone else would.
EDIT
Alternate method:
$array1 = array_map(create_function('$a','$_ = explode("_",$a); return $_[1];'),$array1);
echo in_array(3,$array1) ? "yes" : "no"; // 3 being the example
I would have to agree. If you wish to see is a value exists in an array however just use the 'array_key_exists' function, if it returns true use the value for whatever.

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