PHP - How to loop through array of objects and sum values

Question

I have an array of objects that looks like this:

Array
(
    [0] => stdClass Object
        (
            [ContractorID] => 7049             //<- REMOVE
            [ContractorName] => Supermarket 1  //<-REMOVE
            [SpendAmount] => 615.36            //<-SUM OF ALL ELEMENTS WHERE GroupID IS THE SAME
            [BonusAmount] => 24.61             //<-SUM OF ALL ELEMENTS WHERE GroupID IS THE SAME
            [GroupID] => 1                     //<- RETAIN
            [GroupDescription] => Supermarkets //<- RETAIN
        )

    [1] => stdClass Object
        (
            [ContractorID] => 11233
            [ContractorName] => Supermarket 2
            [SpendAmount] => 858.74
            [BonusAmount] => 34.35
            [GroupID] => 1
            [GroupDescription] => Supermarkets
        )

    [2] => stdClass Object
        (
            [ContractorID] => 19393
            [ContractorName] => Car repair shop 1 
            [SpendAmount] => 386.79
            [BonusAmount] => 15.47
            [GroupID] => 2
            [GroupDescription] => Automotive
        )

    [3] => stdClass Object
        (
            [ContractorID] => 19868
            [ContractorName] => Mike's Autos
            [SpendAmount] => 364.81
            [BonusAmount] => 14.59
            [GroupID] => 2
            [GroupDescription] => Automotive
        )

 )

I want to end up with an array that looks like this:

[0] => stdClass Object
        (
            [SpendAmount] => 1474.1
            [BonusAmount] => 58.96
            [GroupID] => 1
            [GroupDescription] => Supermarkets
        )

    [1] => stdClass Object
        (
            [SpendAmount] => 751.6
            [BonusAmount] => 30.06
            [GroupID] => 2
            [GroupDescription] => Automotive
        )
)

Where BonusAmount is the total of all elements BonusAmount and SpendAmount is the total of all elements SpendAmount.

The summing is simple enough in and of itself, but what I am struggling with is how to retain the GroupID and GroupDescription as I loop through the elements.

Could anyone give me an idea of how I should "retain" the GroupID and GroupDescription syntactically and create an element in my resultant array based on the GroupID? All help much appreciated.

@j your question Could anyone give me an idea. My idea - read a manual. — u_mulder
– u_mulder, Commented Jun 14, 2017 at 13:29

Teun · Accepted Answer · 2017-06-14 13:44:38Z

2

One way of solving this would be to loop through the array of objects checking which ones you've already had and which ones you haven't yet. An example of how to do this is as followed:

        $results = [];
        foreach($objects as $object){
            if(isset($results[$object->GroupID])){
                $results[$object->GroupID]->SpendAmount += $object->SpendAmount;
                $results[$object->GroupID]->BonusAmount += $object->BonusAmount;
            }else{
                $results[$object->GroupID] = [
                    'SpendAmount' => $object->SpendAmount,
                    'BonusAmount' => $object->BonusAmount,
                    'GroupDescription' => $object->GroupDescription
                ];
            }
        }

answered Jun 14, 2017 at 13:44

Teun

9366 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

LF-DevJourney · Accepted Answer · 2017-06-14 13:50:18Z

2

You can traverse the array and sum the items, live demo.

 $r = [];
 foreach($array as $v)
 {
 @$r[$v->GroupID]->SpendAmount += $v->SpendAmount;
 @$r[$v->GroupID]->BonusAmount += $v->BonusAmount;
 @$r[$v->GroupID]->GroupID = $v->GroupID;
 @$r[$v->GroupID]->GroupDescription = $v->GroupDescription;
 }
 print_r(array_values($r));

answered Jun 14, 2017 at 13:50

LF-DevJourney

28.6k30 gold badges170 silver badges321 bronze badges

Comments

Richard Parnaby-King · Accepted Answer · 2017-06-14 13:41:52Z

I've used array_walk_recursive, but array_walk or even a simple foreach would suffice.

//Recreate input data from question
$in = [
        (object) [
            'ContractorID' => '7049',
            'ContractorName' => 'Supermarket 1',
            'SpendAmount' => '615.36',
            'BonusAmount' => '24.61',
            'GroupID' => '1',
            'GroupDescription' => 'Supermarkets',
        ],
        (object) [
            'ContractorID' => '11233',
            'ContractorName' => 'Supermarket 2',
            'SpendAmount' => '858.74',
            'BonusAmount' => '34.35',
            'GroupID' => '1',
            'GroupDescription' => 'Supermarkets',
        ],
        (object) [
            'ContractorID' => '19393',
            'ContractorName' => 'Car repair shop 1 ',
            'SpendAmount' => '386.79',
            'BonusAmount' => '15.47',
            'GroupID' => '2',
            'GroupDescription' => 'Automotive',
        ],
        (object) [
            'ContractorID' => '19868',
            'ContractorName' => 'Mike\'s Autos',
            'SpendAmount' => '364.81',
            'BonusAmount' => '14.59',
            'GroupID' => '2',
            'GroupDescription' => 'Automotive',
        ]
];

//For each object in the array $in, add the object details to a new array.
$return = [];
array_walk_recursive($in, function($a) use (&$return) {
    $found = false;
    //Does this group exist in the array? If so - add spendamount and bonus amount to group.
    foreach($return as $group) {
        if($group->GroupID== $a->GroupID) {
            $found = true;

            $group->SpendAmount += $a->SpendAmount;
            $group->BonusAmount += $a->BonusAmount;

            break;
        }
    }

    //Group not found - create it.
    if(!$found) {
        $return[] = (object) [
            'SpendAmount' => $a->SpendAmount,
            'BonusAmount' => $a->BonusAmount,
            'GroupID' => $a->GroupID,
            'GroupDescription' => $a->GroupDescription,
        ];
    }
});

var_dump($return);
/*
array (size=2)
  0 => 
    object(stdClass)[6]
      public 'SpendAmount' => float 1474.1
      public 'BonusAmount' => float 58.96
      public 'GroupID' => string '1' (length=1)
      public 'GroupDescription' => string 'Supermarkets' (length=12)
  1 => 
    object(stdClass)[7]
      public 'SpendAmount' => float 751.6
      public 'BonusAmount' => float 30.06
      public 'GroupID' => string '2' (length=1)
      public 'GroupDescription' => string 'Automotive' (length=10)
*/

Thank you kindly, sir. I will attempt this and let you know what happens.
This works perfectly, AND I learned something. Thank you so much.

daan.desmedt · Accepted Answer · 2017-06-14 13:25:01Z

0

That is not an array but an object and hence they are treated differently http://php.net/manual/en/language.types.object.php

You access object by $obj->field_name

and you can loop through the object as such

$result = [];
foreach($object as $obj) {
   $result[] = $obj->field1 + $ojb->field2;
}

edited Jun 14, 2017 at 13:25

daan.desmedt

3,8201 gold badge22 silver badges33 bronze badges

answered Jun 14, 2017 at 13:24

Fotoncito

1051 silver badge8 bronze badges

1 Comment

Jacques Over a year ago

Actually, it is an array of objects. The question pertains to how to "flatten" the array based on certain keys in the object, whilst retaining a sum of certain values.

Collectives™ on Stack Overflow

PHP - How to loop through array of objects and sum values

4 Answers 4

Comments

Comments

2 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

2 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related