Group PHP arrays in a loop and create a multidimensional array

Question

I have an associative multidimensional array as below

$data = array();
$data = Array ( 
    [0] => Array ( [class] => 1styear [branch] => IT [Exam] => SEM1 [student name] => Alex [Bio] => Good Boy )
    [1] => Array ( [class] => 2ndyear [branch] => Finance [Exam] => SEM1 [student name] => Mark [Bio] => Intelligent )
    [2] => Array ( [class] => 2ndyear [branch] => IT [Exam] => SEM1 [student name] => Shaun [Bio] => Football Player ) 
    [3] => Array ( [class] => 1styear [branch] => Finance [Exam] => SEM2 [student name] => Mike [Bio] => Sport Player ) 
    [4] => Array ( [class] => 1styear [branch] => IT [Exam] => SEM2 [student name] => Martin [Bio] => Smart  )
    [5] => Array ( [class] => 1styear [branch] => IT [Exam] => SEM1 [student name] => Philip [Bio] => Programmer  )
    )

I need to create a new array based on a similar element from the above array. means I need to create a group of arrays. for example, an element of a class has repeated values ​​of the 1st and 2nd years. therefore, it creates an array of a unique element. then again the class is the parent array and inside the array class there should be an array based on branches and an internal exam array and inside the exam array there should be an associative array of student name and biography.

so basically the array should look like this:

array(
    "1styear" => array(
        "IT" => array(
            "SEM1" => array(
                array(
                    "student name" => "Alex",
                    "Bio" => "Good Boy"
                ),
                array(
                    "student name" => "Philip",
                    "Bio" => "Programmer"
                )
            ),
            "SEM2" => array(
                array(
                    "student name" => "Martin",
                    "Bio" => "Smart"
                )
            )
        )
    ),
    "2ndyear" => array(
        "Finance" => array(
            "SEM1" => array(
                array(
                    "student name" => "Mark",
                    "Bio" => "Intelligent"
                )
            ),
            "SEM2" => array(
                array(
                    "student name" => "Mike",
                    "Bio" => "Sport Player"
                )
            )
        )
    )
);

To make a group based on class i, as shown below, which works fine, but how to create an array inside this

$classgroup = array();  
    foreach($data as $inarray){

         $classgroup[$inarray['class']][] = $inarray;
    }
    $classarray = array();
    foreach($classgroup as $key => $value){
            echo $key; // output is 1styear and secondyear 
            create array like above
    }

--------------------------------- EDIT ---------- ------------------------

foreach($data as $array){
        $grouped[$array["class"]][$array["branch"]][$array["Exam"]][]=array("student name"=>$array["student name"],"Bio"=>$array["Bio"]);
} 

o/p o/p,

o/p

array(
    '1styear' =>
        array (
            0 =>
                array(
                    'Exam' => 'SEM1',
                    'branch' =>
                        array (
                            0 => 'IT'
                        ),
                ),
            1 =>
                array(
                    'Exam' => 'SEM2',
                    'branch' =>
                        array (
                            0 => 'IT'
                        ),
                ),
        ),
    '2ndyear' =>
        array (
            0 =>
                array(
                    'Exam' => 'SEM1',
                    'branch' =>
                        array (
                            0 => 'Finance',
                        ),
                ),
            1 =>
                array(
                    'Exam' => 'SEM2',
                    'branch' =>
                        array (
                            0 => 'Finance'
                        ),
                )
        ),
)

, o/p

foreach($data as $array){
        $grouped[$array["class"]][]=array("Exam"=>$array["Exam"],"branch"=>$array["branch"]);
}

Answer 1

!

foreach($data as $array){
        $grouped[$array["class"]][$array["branch"]][$array["Exam"]][]=array("student name"=>$array["student name"],"Bio"=>$array["Bio"]);
}

$grouped :

Array(
    [1styear] => Array(
        [IT] => Array(
            [SEM1] => array(
                [0] => array(
                    [student name] => Alex,
                    [Bio] => Good Boy
                ),
                [1] => array(
                    [student name] => Philip,
                    [Bio] => Programmer
                )
            ),
            [SEM2] => array(
                [0] => array(
                    [student name] => Martin,
                    [Bio] => Smart
                )
            )
        ),
        [Finance] => array(
            [SEM2] => array(
                [0] => array(
                    [student name] => Mike,
                    [Bio] => Sport Player
                )
            )
        )
    ),
    [2ndyear] => array(
        [Finance] => array(
            [SEM1] => array(
                [0] => array(
                    [student name] => Mark,
                    [Bio] => Intelligent
                )
            )
        ),
        [IT] => array(
            [SEM1] => array(
                [0] => array(
                    [student name] => Shaun,
                    [Bio] => Football Player
                )
            )
        )
    )
)

---

/. , . :

<?php
$data = array ( 
    array ( "class"=>"1styear","branch"=>"IT","Exam"=>"SEM1","student name"=>"Alex","Bio"=>"Good Boy"),
    array ( "class"=>"2ndyear","branch"=>"Finance","Exam"=>"SEM1","student name"=>"Mark","Bio"=>"Intelligent" ),
    array ( "class"=>"2ndyear", "branch"=>"IT","Exam"=>"SEM1","student name"=>"Shaun","Bio"=>"Football Player" ), 
    array ( "class"=>"1styear","branch"=>"Finance","Exam"=>"SEM2","student name"=>"Mike","Bio"=>"Sport Player" ), 
    array ( "class"=>"1styear","branch"=>"IT","Exam"=>"SEM2","student name"=>"Martin","Bio"=>"Smart"),
    array ( "class"=>"1styear","branch"=>"IT","Exam"=>"SEM1","student name"=>"Philip","Bio"=>"Programmer"  )
);
$class_keys=array_unique(array_column($data,"class"));  // create array of unique class values
$Exam_keys=array_unique(array_column($data,"Exam"));  // create array of unique Exam values
foreach($class_keys as $class_key){
    $i=0;  // "class" subarray index
    foreach($Exam_keys as $Exam_key){
        $q=array("class"=>$class_key,"Exam"=>$Exam_key);  // this array can have 1 or more pairs
        // create an array only of rows where $q key-value pairs exist
        $qualifying_array=array_filter(
            $data,
            function($val)use($q){  
                if(count(array_intersect_assoc($val,$q))==count($q)){  // total pairs found = total pairs sought
                    return $val;
                }
            },
            ARRAY_FILTER_USE_BOTH
        );
        foreach($qualifying_array as $qa){  // push appropriate values into array
            $grouped2[$class_key][$i]["Exam"]=$qa["Exam"];
            $grouped2[$class_key][$i]["branch"][]=$qa["branch"];
        }
        if(isset($grouped2[$class_key][$i]["branch"])){  // ensure no duplicate values in "branch" subarray
            $grouped2[$class_key][$i]["branch"]=array_unique($grouped2[$class_key][$i]["branch"]);
        }
        ++$i;  // increment the index for each "class" subarray
    }
}
echo "<pre>";
print_r($grouped2);
echo "</pre>";

, , , , . , .

array(
    [1styear]=>array(
        [0]=>array(
            [Exam]=>SEM1
            [branch]=>array(
                [0]=>IT
            )
        ),
        [1]=>array(
            [Exam]=>SEM2
            [branch]=>array(
                [0]=>Finance,
                [1]=>IT
            )
        )
    ),
    [2ndyear]=>array(
        [0]=>array(
            [Exam]=>SEM1
            [branch]=>array(
                [0]=>Finance,
                [1]=>IT
            )
        )
    )
)

Answer 2

, - ( )?

$newData = [];

foreach ($data as $row) {
   $student = [
      'student name' => $row['student name'],
      'Bio' => $row['Bio']
   ];
   $newData[$row['class']][$row['branch']][$row['exam']][] = $student;
}