如何在JSON中找到2个不同变量的最小值，并用该值减去其他元素

Question

I need to find the smallest value of 2 variables in JSON object of particular key and subtract all keys with that value. Kindly lookinto following JSON Data

$print = '{"Table":[
{"Column":2,"Length":1,"Number":"A4","Row":12,"zindex":0}, 
{"Column":2,"Length":1,"Number":"A3","Row":11,"zindex":0},
{"Column":2,"Length":1,"Number":"A2","Row":9,"zindex":1},
{"Column":2,"Length":1,"Number":"A1","Row":8,"zindex":1},  
{"Column":3,"Length":1,"Number":"B4","Row":12,"zindex":0},
{"Column":3,"Length":1,"Number":"B3","Row":11,"zindex":0},
{"Column":3,"Length":1,"Number":"B2","Row":9,"zindex":0},
{"Column":3,"Length":1,"Number":"B1","Row":8,"zindex":0},
{"Column":4,"Length":1,"Number":"C4","Row":12,"zindex":0},
{"Column":4,"Length":1,"Number":"C3","Row":11,"zindex":0},  
{"Column":4,"Length":1,"Number":"C2","Row":9,"zindex":0},
{"Column":4,"Length":1,"Number":"C1","Row":8,"zindex":0}],"ResponseStatus":200,"Message":null}';

I want above JSON Data as given below.

$print = '{"Table":[
    {"Column":2,"Length":1,"Number":"A4","Row":1,"zindex":0}, 
    {"Column":2,"Length":1,"Number":"A3","Row":0,"zindex":0},
    {"Column":2,"Length":1,"Number":"A2","Row":1,"zindex":1},
    {"Column":2,"Length":1,"Number":"A1","Row":0,"zindex":1},  
    {"Column":3,"Length":1,"Number":"B4","Row":1,"zindex":0},
    {"Column":3,"Length":1,"Number":"B3","Row":0,"zindex":0},
    {"Column":3,"Length":1,"Number":"B2","Row":1,"zindex":1},
    {"Column":3,"Length":1,"Number":"B1","Row":0,"zindex":1},
    {"Column":4,"Length":1,"Number":"C4","Row":1,"zindex":0},
    {"Column":4,"Length":1,"Number":"C3","Row":0,"zindex":0},  
    {"Column":4,"Length":1,"Number":"C2","Row":1,"zindex":1},
    {"Column":4,"Length":1,"Number":"C1","Row":0,,"zindex":1}],"ResponseStatus":200,"Message":null}';

In the above JSON data kindly look into Row and zindex. zindex has two values "0 and 1", here I want php code to find smallest value of zindex 0 separately and subtract remaining values of zindex 0 alone and same with zindex 1.

I have a PHP code that finds minimum value of row and subtract remaining rows with that value. But I dont know how to do it separately for different zindexs.

$rows = array();
$print = json_decode($print, true); // decode
foreach($print['Table'] as $val) { $rows[] = $val['Row']; }
$least = min($rows); // get least // $least = min(array_column($print['Table'], 'Row'));
foreach($print['Table'] as &$val) {
    $val['Row'] -= $least; // make subtractions
}
$print = json_encode($print); // re encode

Kindly help me to solve this problem in PHP.

Answer 1

Try to replace the first foreach by:

foreach($print['Table'] as $val) {
    if (!isset($rows[$val['zindex']])) {
        $rows[$val['zindex']] = array();
    }
    $rows[$val['zindex']][] = $val['Row'];
}

Instead of having a 1-dimensional array with values, the array is 2-dimensional, having all Row values for each value of zindex.

Then, $least should be an array as well:

$least = array();
foreach ($rows as $zindex = $row) {
    $least[$zindex] = min($row);
}

That will calculate the minimum value for each value of zindex separately.

Finally, the last foreach should discriminate for zindex as well:

foreach ($print['Table'] as &$val) {
    $val['Row'] -= $least[$val['zindex']];
}

Success!