How to combine 2 arrays into single one? - php

Question

I have 2 arrays, as you will see bellow, and I want theme to combine into a single one. First 2 arrays have sub-arrays with a sum and a month. The result array(3rd), must have the sum of first 2 arrays for the same month.
array:3 [
0 => array:2 [
"sum" => 179.0
"month" => "2016-01"
]
1 => array:2 [
"sum" => 34.0
"month" => "2016-02"
]
2 => array:2 [
"sum" => 67.0
"month" => "2016-03"
]
]
array:2 [
0 => array:2 [
"sum" => 143.25
"month" => "2016-01"
]
1 => array:2 [
"sum" => 479.0
"month" => "2016-03"
]
]
Total:
array:3 [
0 => array:3 [
"sum" => 313.25
"month" => "2016-01"
]
1 => array:2 [
"sum" => 34.0
"month" => "2016-02"
]
2 => array:2 [
"sum" => 546.0
"month" => "2016-03"
]
]
What I tried:
for($i=0;$i<count($com1);$i++){
for ($j=0; $j < count($com2); $j++) {
if($com1[$i]['month'] == $com2[$j]['month']){
$total = $com1[$i]['sum']+$com2[$j]['sum']
}
}
}
But it doesn't give the result I want
I am abit noob...I hope someone can help. Thanks

Answer 1

Try this:
$com1 = [
0 => [
'sum' => 179.0,
'month' => '2016-01'
],
1 => [
'sum' => 34.0,
'month' => '2016-02'
],
2 => [
'sum' => 67.0,
'month' => '2016-03'
]
];
$com2 = [
0 => [
'sum' => 143.25,
'month' => '2016-01'
],
1 => [
'sum' => 479.0,
'month' => '2016-03'
]
];
$total = [];
foreach ($com1 as $data) {
$total[$data['month']] = $data;
}
foreach ($com2 as $data) {
if (!isset($total[$data['month']])) {
$total[$data['month']] = [
'sum' => 0,
'month' => $data['month']
];
}
$total[$data['month']]['sum'] += $data['sum'];
}
print_r($total);

Answer 2

Here is a solution that generates a non-associative array (as you indicated in your question):
$month_idx = []; // helper to identify at which index a certain month is stored
$result = [];
foreach (array_merge($data1, $data2) as $idx => $row) {
$month = $row["month"];
if (!isset($month_idx[$month])) {
$month_idx[$month] = count($result);
$result[] = $row;
} else {
$result[$month_idx[$month]]["sum"] += $row["sum"];
}
}
var_export($result);
When $data1 and $data2 are:
$data1 = array (
array(
"sum" => 179.0,
"month" => "2016-01"
),
array(
"sum" => 34.0,
"month" => "2016-02"
),
array(
"sum" => 67.0,
"month" => "2016-03"
)
);
$data2 = array (
array(
"sum" => 143.25,
"month" => "2016-01"
),
array(
"sum" => 479.0,
"month" => "2016-03"
)
);
Then output is:
array (
0 =>
array (
'sum' => 322.25,
'month' => '2016-01',
),
1 =>
array (
'sum' => 34,
'month' => '2016-02',
),
2 =>
array (
'sum' => 546,
'month' => '2016-03',
),
)