Counting occurrences in an array that has more than 1 key - php

Question

I'm trying to get the occurrences of an array taking in count 1 key value, for example:
$newarray[0] = [
'id' => '2',
'date' => '2016-04-22'
];
$newarray[1] = [
'id' => '2',
'date' => '2016-04-13'
];
$newarray[2] = [
'id' => '2',
'date' => '2016-04-12'
];
$newarray[3] = [
'id' => '1',
'date' => '2016-03-11'
];
$newarray[4] = [
'id' => '2',
'date' => '2016-03-05'
];
$newarray[5] = [
'id' => '1',
'date' => '2016-03-01'
];
I want to transform this, to something like this:
Array ( [0] => Array ( [id] => 1 [date] => 2016-03-11 [occurences] => 2 ) [1] => Array ( [id] => 2 [date] => 2016-04-22 [occurences] => 4 ) )
I tried doing this:
$cleanarray;
$newarray2=$newarray;
$newarray;
$k=0;
$num=1;
for($i=0; $i<count($newarray); $i++){
for($j=1; $j<count($newarray2); $j++){
if($newarray2[$j]["id"]==$newarray[$i]["id"]){
$num++;
}
}
$cleanarray[$k] = [
'id' => $newarray[$i]["id"],
'date' => $newarray[$i]["date"],
'occurences' => $num
];
$k++;
$num=0;
}
But a lot of items repeat, with the same occurrences but several times, and in other cases the repeated items (with same id) would have different occurrences, so I don't know what can I do, I know that there is a function of:
$occurences = array_count_values($array);
But it doesn't work in this case, how can I approach to the solution?

Answer 1

I know what are you looking for, but I think this could solve your problems:
$newarray[0] = [
'id' => '2',
'date' => '2016-04-22'
];
$newarray[1] = [
'id' => '2',
'date' => '2016-04-12'
];
$newarray[2] = [
'id' => '2',
'date' => '2016-04-12'
];
$newarray[3] = [
'id' => '1',
'date' => '2016-03-11'
];
$newarray[4] = [
'id' => '2',
'date' => '2016-03-05'
];
$newarray[5] = [
'id' => '1',
'date' => '2016-03-01'
];
foreach($newarray as $key => $value){
if(isset($found[$value['id']][$value['date']])) {
$found[$value['id']][$value['date']]++;
} else {
$found[$value['id']][$value['date']] = 1;
}
}
print_r($found);
this will return something like:-
Array
(
[2] => Array
(
[2016-04-22] => 1
[2016-04-12] => 2
[2016-03-05] => 1
)
[1] => Array
(
[2016-03-11] => 1
[2016-03-01] => 1
)
)

Answer 2

Using temporary keys for this process will be the most performant way. Temporary keys simplify the output array task, requiring less and faster checking. If you wish to sort on id after the result array is generated, the temporary keys allow a simple ksort() call.
Code: (Demo)
$newarray=[
['id' => '2','date' => '2016-04-22'],
['id' => '2','date' => '2016-04-13'],
['id' => '2','date' => '2016-04-12'],
['id' => '1','date' => '2016-03-11'],
['id' => '2','date' => '2016-03-05'],
['id' => '1','date' => '2016-03-01']
];
foreach($newarray as $a){
if(!isset($result[$a['id']])){
$result[$a['id']]=array_merge($a,['occurrences'=>1]); // use id as temp key, preserve first found date
}else{
++$result[$a['id']]['occurrences']; // only update occurrences to preserve date
}
}
ksort($result); // optionally sort on id ASC
var_export(array_values($result)); // remove temporary keys from first level and print to screen
Output:
array (
0 =>
array (
'id' => '1',
'date' => '2016-03-11',
'occurrences' => 2,
),
1 =>
array (
'id' => '2',
'date' => '2016-04-22',
'occurrences' => 4,
),
)

Answer 3

You can do it like below:-
$final_array = array();
foreach($newarray as $arr){
if(!in_array($arr['id'],array_keys($final_array))){
$final_array[$arr['id']] = $arr;
$final_array[$arr['id']]['occurences'] = 1;
}else{
$final_array[$arr['id']]['occurences'] += 1;
}
}
$final_array= array_values($final_array);
print_r($final_array);
Output:- https://eval.in/847242
Note:- if you want final array to be ascending order of id then use usort() function like below:-
function cmpId($a, $b) {
return ($a['id'] - $b['id']);
}
usort($final_array, "cmpId");
print_r($final_array);
Output:- https://eval.in/847245