php array_merge_recursive preserving numeric keys - php

I would simply like to merge
$a = array("59745506"=>array("up" => 0,));
$b = array("59745506"=>array("text" => "jfrj"));
$c = array_merge_recursive_new($a, $b);
result:
Array
(
[0] => Array
(
[up] => 0
)
[1] => Array
(
[text] => jfrj
)
)
expected result:
Array
(
[59745506] => Array
(
[up] => 0
[text] => jfrj
)
)
the 2nd comment in http://www.php.net/manual/en/function.array-merge-recursive.php is working, is it the best solution for my case (where I need to merge arrays with multiple numeric keys, and with 2 levels)?
another workaround would be to implement it with array_map(function ()...

The array_replace_recursive() function looks to be what you need.
$a = array("59745506" => array("up" => 0,));
$b = array("59745506" => array("text" => "jfrj"));
$c = array_replace_recursive($a, $b);
var_export($c);
// array (
// 59745506 =>
// array (
// 'up' => 0,
// 'text' => 'jfrj',
// ),
// )

Your expectation fails as the key of the $a and $b is numeric(!), even though you denoted it as a string literal (cf. PHP: Arrays -> Syntax).
I think whether or not there is a better solution depends on what you exactly need. It might be simpler than merging recursively:
1) Are you sure that every value inside the $a and $b arrays will always be an array again?
2) What is supposed to happen if these arrays share a common key (i.e. if "text" was again "up" in your example)? Keep merging recursively or not?

Related

Spliting .txt file lines in to multi-layered array key value pairs then sorting it

Since this question has a long explanation, I'll ask the question, then have the explanation below -- Can you sort a multidimensional array by their internal array key value, or is there a better way to get around sorting key value pairs that will have inevitable duplicates, than just using an array?
I am mostly unfamiliar with using PHP and want to learn how to store data.
The very simple example I made is just two HTML form inputs for a score and a name and a PHP file to handle the input to be stored in a plain .txt file, which was originally written with the pattern
42|John
32|Jane
25|John
I was able to successfully split the data, sort it, add the new inputted values then store it all back in the text file to be displayed somewhere else, using the name as the key and the score as the value.
I did all this only to realize that it would only store sort and display the last value associated with each name (i.e.)
42|John
32|Jane
25|John
would be sorted to
32|Jane
25|John
because you, obviously, can't have two of the same keys in an array, which is something I completely overlooked.
My solution, currently is to have an extra number that is unique to each name/score pair, which I formatted in the text file as
1|42|John
2|32|Jane
3|25|John
I then split them into a multidimensional array using this foreach loop
foreach($arr as $key => $value) {
$lineData = explode("|", $value);
$scores[$lineData[0]] = array($lineData[1] => $lineData[2]);
}
To get this output
Array
(
[1] => Array
(
[42] => John
)
[2] => Array
(
[32] => Jane
)
[3] => Array
(
[25] => John
)
)
which avoids overwriting any duplicate names or scores, but leaves me in a position where I can't (to my knowledge) use arsort() to sort the array in to highest to lowest.
You can use array_multisort for that, in combination with array_column. Because the key values are strings, you need to also convert them to integers, for which you can use array_map("intval", ...):
foreach($arr as $value) {
$result[] = explode("|", $value);
}
array_multisort(array_map("intval", array_column($result, 0)), $result);
After the above code has run, $result will be sorted by the key values:
[
['25', 'John'],
['32', 'Jane'],
['42', 'John']
]
To reverse the order, apply array_reverse to the result.
Alternative
You could also decide to sort the original array without conversion to a 2D array, and sort it with a custom sort callback, using usort and (again) intval:
usort($arr, function ($a, $b) {
return intval($a) - intval($b);
});
Then $arr will be sorted to:
[
'25|John',
'32|Jane',
'42|John'
]
To reverse the order, switch the position of $a and $b in the sort callback function:
return intval($b) - intval($a);
If we make a small change to your foreach iteration like this:
foreach($arr as $key => $value) {
$lineData = explode("|", $value);
$scores[] = array('score' => $lineData[1], 'name' => $lineData[2]);
}
Your array will have:
Array
(
[0] => Array
(
[score] => 42
[name] => John
)
[1] => Array
(
[score] => 32
[name] => Jane
)
[2] => Array
(
[score] => 25
[name] => John
)
)
You can use the uasort function, which takes the array to sort, and an user-defined function to do the sorting. The code would look like this:
function compare($a, $b)
{
if ($b['score'] == $a['score']) {
if ($a['name'] == $b['name']) {
return 0;
} elseif ($a['name'] < $b['name']) {
return -1;
} else {
return 1;
}
} else {
return ($b['score'] - $a['score']);
}
}
print_r($scores);
uasort($scores, 'compare');
print_r($scores);
Which gives the following result:
Array
(
[1] => Array
(
[score] => 32
[name] => Jane
)
[2] => Array
(
[score] => 25
[name] => John
)
[0] => Array
(
[score] => 42
[name] => John
)
)
When you use a user-defined function for the sorting you need to return one of 3 values (0 of the values as equal, -1 if $a < $b, and 1 if $b > $a. In this case we're sorting first by score (descending), then by name (ascending). Since you need to order from highest to lowest score, the comparison is $b against $a, for ascending order is $a against $b. I didn't consider the extra number necessary. If you need it then change this line:
$scores[] = array('score' => $lineData[1], 'name' => $lineData[2]);
To this:
$scores[$lineData[0]] = array('score' => $lineData[1], 'name' => $lineData[2]);

combine multi-dimensional array on value from JSON

I have 2 api end points that load JSON data...
1. subject matter experts
Array
(
[0] => Array
(
[ExpertiseId] => 1
[IndustryId] => 1
[PersonId] => 3
)
...
)
people database
Array
(
[0] => Array
(
[Id] => 1
[Name] => Joe
[Office] => New York
)
....
)
I'd like to pass both functions into an array, specify to merge on [matter.PersonId] => [people.Id] so the returned array would become
Array
(
[0] => Array
(
[ExpertiseId] => 1
[IndustryId] => 1
[PersonId] => 3
[Id] => 1
[Name] => Joe
[Office] => New York
)
...
)
You have to iterate over both arrays and reorganize the data in such a way that merging can happen. In practice that means rekeying the first array by PersonId and the second by Id; this is very easy to do with array_column:
$matter = array_column($matter, null, 'PersonId');
$people = array_column($people, null, 'Id');
At this point only a simple task is left: merging the items (arrays) that share the same key in both $matter and $people.
In a perfect world that would be an one-liner with array_merge_recursive, but that function does not actually merge arrays that have integer keys like these (the ids we used as keys are integers). So a little standard iteration is in order: pick one of the arrays and merge its contents with the other:
foreach ($people as $id => $data) {
// If there's a guarantee that both arrays will definitely have the same
// set of keys (ids) so that $matter[$id] is guaranteed to exist,
// you can also use the simpler: $matter[$id] += $data
$matter[$id] = isset($matter[id]) ? $matter[$id] + $data : $data;
}
...and now $matter has all the data merged together.
Try array_merge()
$newArray = array_merge(first_array, second_array);

Remove duplicated elements of associative array in PHP

$result = array(
0=>array('a'=>1,'b'=>'Hello'),
1=>array('a'=>1,'b'=>'other'),
2=>array('a'=>1,'b'=>'other'),
);
If it is duplicated removed it, so the result is as follows:
$result = array(
0=>array('a'=>1,'b'=>'Hello'),
1=>array('a'=>1,'b'=>'other')
);
Could any know to do this?
Thanks
Regardless what others are offering here, you are looking for a function called array_uniqueDocs. The important thing here is to set the second parameter to SORT_REGULAR and then the job is easy:
array_unique($result, SORT_REGULAR);
The meaning of the SORT_REGULAR flag is:
compare items normally (don't change types)
And that is what you want. You want to compare arraysDocs here and do not change their type to string (which would have been the default if the parameter is not set).
array_unique does a strict comparison (=== in PHP), for arrays this means:
$a === $b TRUE if $a and $b have the same key/value pairs in the same order and of the same types.
Output (Demo):
Array
(
[0] => Array
(
[a] => 1
[b] => Hello
)
[1] => Array
(
[a] => 1
[b] => other
)
)
First things first, you can not use plain array_unique for this problem because array_unique internally treats the array items as strings, which is why "Cannot convert Array to String" notices will appear when using array_unique for this.
So try this:
$result = array(
0=>array('a'=>1,'b'=>'Hello'),
1=>array('a'=>1,'b'=>'other'),
2=>array('a'=>1,'b'=>'other')
);
$unique = array_map("unserialize", array_unique(array_map("serialize", $result)));
print_r($unique);
Result:
Array
(
[0] => Array
(
[a] => 1
[b] => Hello
)
[1] => Array
(
[a] => 1
[b] => other
)
)
Serialization is very handy for such problems.
If you feel that's too much magic for you, check out this blog post
function array_multi_unique($multiArray){
$uniqueArray = array();
foreach($multiArray as $subArray){
if(!in_array($subArray, $uniqueArray)){
$uniqueArray[] = $subArray;
}
}
return $uniqueArray;
}
$unique = array_multi_unique($result);
print_r($unique);
Ironically, in_array is working for arrays, where array_unique does not.

PHP Multidimensional Array First Object

I have an array in PHP that looks like
Array ( [123654] => Array ( [0] => 123456789123456789 [1] => 1 [2] => 06/24/2011 [3] => 06/24/2012 [4] => 12355.44 [5] => 55321.55 ) )
I know in javascript I could access the data I need by doing array[0][0], how would I go about doing this in PHP. It is the 123456789123456789 value that I'm looking at getting.
Try this
array_slice($array, 0, 1);
http://php.net/array_slice
If you don't know the exact keys, you could do something like this:
$a = array_values($my_array);
$b = array_values($a[0]);
echo $b[0];
array_values replaces the keys by simple numbers from 0 to n-1 (where n is the count of values), by that you can access your desired value with the indexes [0][0]. See more here
http://codepad.org/YXu6884R
Here you go. See above for proof. The methodology from #azat is not explicit enough and is prone to risk if the elements of the array or sub array are re-arranged or if the key value for the super array changes.
$my_array = array( 123654 => array( 0 => '123456789123456789', 1 => '1', 2 => '06/24/2011', 3 => '06/24/2012', 4 => '12355.44', 5 => '55321.55' ) );
echo $my_array['123654'][0];
Try
$first = array_shift(array_values($array));
http://php.net/manual/en/function.array-shift.php

php assoc array

I have two assoc array i want to creat one array out of that
E.g
a(a=>1
b=>3
f=>5
)
b(a=>4
e=>7
f=>9
)
output must be
c(
a=>1
b=>3
f=>5
a=>4
e=>7
f=>9
)
i am new in php
Use array_merge(). Your resulting array CAN NOT have more than one entry for the same key, so the second a => something will overwrite the first.
Use the + operator to return the union of two arrays.
The new array is constructed from the left argument first, so $a + $b takes the elements of $a and then merges the elements of $b with them without overwriting duplicated keys. If the keys are numeric, then the second array is just appended.
This ey difference of the + operator and the function, array_merge is that array merge overwrites duplicated keys if the latter arguments contain that key. The documentation puts it better:
If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.
If the keys are different, then use array_merge()
<?php
$a1=array("a"=>"Horse","b"=>"Cat");
$a2=array("c"=>"Cow");
print_r(array_merge($a1,$a2));
?>
OUTPUT:
Array ( [a] => Horse [b] => Cat [c] => Cow )
If the keys are the same, then use array_merge_recursive()
<?php
$ar1 = array("color" => array("favorite" => "red"), 5);
$ar2 = array(10, "color" => array("favorite" => "green", "blue"));
$result = array_merge_recursive($ar1, $ar2);
print_r($result);
?>
OUTPUT:
Array
(
[color] => Array
(
[favorite] => Array
(
[0] => red
[1] => green
)
[0] => blue
)
[0] => 5
[1] => 10
)

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