How to get max and min value in a multidimensional array - php

Question

I have this array :
array(8) {
[0]=>
array(2) {
["ticket_type"]=>
string(9) "normal"
["ticket_price"]=>
string(5) "82.00"
}
[1]=>
array(2) {
["ticket_type"]=>
string(9) "cheaper"
["ticket_price"]=>
string(5) "62.00"
}
[2]=>
array(2) {
["ticket_type"]=>
string(9) "normal"
["ticket_price"]=>
string(6) "182.00"
}
[3]=>
array(2) {
["ticket_type"]=>
string(9) "cheaper"
["ticket_price"]=>
string(6) "162.00"
}
[4]=>
array(2) {
["ticket_type"]=>
string(9) "normal"
["ticket_price"]=>
string(6) "103.00"
}
[5]=>
array(2) {
["ticket_type"]=>
string(9) "cheaper"
["ticket_price"]=>
string(5) "63.00"
}
[6]=>
array(2) {
["ticket_type"]=>
string(9) "normal"
["ticket_price"]=>
string(6) "203.00"
}
[7]=>
array(2) {
["ticket_type"]=>
string(9) "cheaper"
["ticket_price"]=>
string(6) "163.00"
}
}
I want to get the min and max price for "normal" and "cheap" ticket category, there will be more ticket categories, so can't hard code it, will get from DB, how can I do that? I'm using PHP 5.6 now, need export as array or json, Let me know if need more details.
Thank you

Answer 1

You can do it at the SQL level:
SELECT MIN(ticket_price) AS min_ticket_price, MAX(ticket_price) as max_ticket_price, ticket_type
FROM {your_table_name}
WHERE {your_conditions}
GROUP BY ticket_type

Answer 2

If you still want to do it in PHP you can just loop the array and to sort the ticket types then get the min and max values.
foreach($arr as $ticket){
$new[$ticket["ticket_type"]][] = $ticket["ticket_price"];
}
// loop the new array to only get the max and min values of each ticket type
foreach($new as $key => $n){
$res[$key]["max"] = max($n);
$res[$key]["min"] = min($n);
}
output:
array(2) {
["normal"]=>
array(2) {
["max"]=>
string(6) "203.00"
["min"]=>
string(5) "82.00"
}
["cheaper"]=>
array(2) {
["max"]=>
string(6) "163.00"
["min"]=>
string(5) "62.00"
}
}
https://3v4l.org/RcCHZ

Answer 3

Here is a solution to do on the php level:
$prices = [
["ticket_type"=>"normal", "ticket_price"=>"82.00"],
["ticket_type"=>"cheaper", "ticket_price"=>"62.00"],
["ticket_type"=>"normal", "ticket_price"=>"182.00"],
["ticket_type"=>"cheaper", "ticket_price"=>"162.00"],
["ticket_type"=>"normal", "ticket_price"=>"103.00"],
["ticket_type"=>"cheaper", "ticket_price"=>"63.00"],
["ticket_type"=>"normal", "ticket_price"=>"203.00"],
["ticket_type"=>"cheaper", "ticket_price"=>"163.00"],
];
// STEP:1 group by ticket types
$grouped_array = [];
foreach($prices as $price) {
$ticket_type = $price["ticket_type"];
$grouped_array[$ticket_type][] = $price["ticket_price"];
}
/*
$grouped_array = [
"normal" => ["82.00", "182.00", "103.00", "203.00"],
"cheaper => ["62.00", "162.00", "63.00", "163.00"]
];
*/
function minMax($type_array) {
$min_max = ['min'=> min($type_array), 'max'=>max($type_array)];
return $min_max;
}
// STEP 2: find min and max in each category
$min_max = [];
foreach($grouped_array as $type => $prices) {
$min_max[$type] = minMax($prices);
}
/*
$min_max = [
"normal" => ["min"=>"82.00", "max"=>"203.00"],
"cheaper => ["min"=>"62.00", "max"=>"163.00"]
];
*/
However, doing it on the database layer is best in your case. this answers "How to get max and min value in a multidimensional array".