Comparing 2 arrays and adding similar values - php

Question

I have 2 arrays in PHP. One of them holds a list of dates, the other a list of numbers.
Array1
(
[0] => 2010-06-14
[1] => 2010-06-14
[2] => 2010-06-14
[3] => 2014-01-26
[4] => 2014-01-26
)
Array2
(
[0] => 120
[1] => 100
[2] => 60
[3] => 140
[4] => 30
)
The value [0] in Array2 belongs with the date [0] in Array1. What I am trying to do is add all of the values in Array2 together, based on the date. Any dates that match should have their values added together. So for example at the end I would like something like:
$date = 2010-06-14;
$value = 280;
$date = 2014-01-26;
$value = 170;
...and so on.
I've searched though the site but was unable to find exactly what I needed. Any help would be appreciated...

Answer 1

You can iterate $values, and get the corresponding date from $dates to use as the key in your result array.
foreach ($values as $key => $value) {
$result[$dates[$key]] = $value + ($result[$dates[$key]] ?? 0);
}
The output will be like this:
array (size=2)
'2010-06-14' => int 280
'2014-01-26' => int 170

Answer 2

$sum=0; // New Element
$Array3[][]=0; // New 2D array
$p=0; // Counter for 2D array
for($i=0;$i<5;$i++) // Single loop for traversing
{
$date=Array1[$i]; // Start for a date
while($date==Array1[$i]){ // For for Similar date
$sum=$sum+Array2[$i]; // Adding values of similar date
$i++; // Increment array
}
$Array3[$p]["date"]=$date; // Array3 date element
$Array3[$p]["sum"]=$sum; // Array4 date element
$i--; // Reducing a value which is incremented in while loop
}
Array3 is like
Array3
(
[0] => array( 'date' => " ",'sum' => " ")
[1] => array( 'date' => " ",'sum' => " ")
)

Answer 3

Are you trying to count all of the values in Array2 that have an entry in Array1 that matches some predefined target value?
If so, this for loop version should work:
private function forLoopVersion($array1, $array2, $target) {
$result = 0;
for ($i = 0; $i < count($array1); ++$i) {
if ($array1[$i] == $target) {
$result += $array2[$i];
}
}
return $result;
}
Also, this foreach loop version might work, but I do not know if the $key for $array1 can be used to index an element in $array2. You could try it:
private function foreachLoopVersion($array1, $array2, $target) {
$result = 0;
foreach ($array1 as $key => $value) {
if ($value == $target) {
$result += $array2[$key];
}
}
return $result;
}

Answer 4

$newArray = array();
for($i = 0; $i < count(Array1); $i++) {
$newArray[$Array1[$i]] = $Array2[$i];
}
echo $newArray[$date1] + $newArray[$date2];
Put the dates as keys to for easy math.