I have two arrays. I am comparing those arrays through loop and calculating results but It is always making ascending order by the array indexes. I need to create order after calculation with those values in descending order.
<?php
$correctAnswers = [
['name'=> 1, 'value'=> 4],
['name'=> 1, 'value'=> 1]
];
$submittedStudentData =[
[101, 0, 1, 1],
[102, 0, 4, 1]
];
if(!is_array($submittedStudentData))
{
$submittedStudentData = json_decode($submittedStudentData);
}
for ($index = 0; $index < count($submittedStudentData); $index++){
// get each student data
$studentData = $submittedStudentData[$index];
// get the student roll number
$studentId = $studentData[0];
// initialize the total result with zero pre value
$totalResult = 0;
// loop through the student's submitted answer
for ($i = 2; $i < count($studentData); $i++)
{
if ((int)$studentData[$i] === (int)$correctAnswers[$i - 2]["value"])
{
$totalResult++;
}
}
// final result for this student
echo 'Student with roll number '. $studentId .' scores '. $totalResult."\n";
}
?>
The output is
Student with roll number 101 scores 1
Student with roll number 102 scores 2
I need the output by descending order with scores.
Student with roll number 102 scores 2
Student with roll number 101 scores 1
create an array placeholder for studentId
and totalScores
then reverse the array is much easier I think
<?php
$correctAnswers = [
['name'=> 1, 'value'=> 4],
['name'=> 1, 'value'=> 1]
];
$submittedStudentData =[
[101, 0, 1, 1],
[102, 0, 4, 1]
];
if(!is_array($submittedStudentData))
{
$submittedStudentData = json_decode($submittedStudentData);
}
$s_data = [];
for ($index = 0, $c = count($submittedStudentData); $index < $c; $index++){
// get each student data
$studentData = $submittedStudentData[$index];
// get the student roll number
$studentId = $studentData[0];
// initialize the total result with zero pre value
$totalResult = 0;
// loop through the student's submitted answer
for ($i = 2, $x = count($studentData) ; $i < $x; $i++)
{
if ((int)$studentData[$i] === (int)$correctAnswers[$i - 2]["value"])
{
$totalResult++;
}
}
$s_data[] = ['studentId' =>$studentId, 'scores'=>$totalResult];
// final result for this student
}
$r = array_reverse($s_data);
foreach($r as $d)
{
echo 'Student with roll number '. $d['studentId'] .' scores '. $d['scores']."\n";
}
?>
demo: https://3v4l.org/Fgsi9
[edit]
I neglect that you require sorting on the score
value. In this case, you need to compare the value from the new array.
demo: https://3v4l.org/amfBa
more on this sorting based on array key/value here How to Sort a Multi-dimensional Array by Value