Numbers inputted always reset in php - php

Question

** Here are the Codes that i use**
** I use this for recording of the scores, there 5 zeros cause there are more 3 students
$Students_C1= array(0,0,0,0,0);
$Students_C2= array(0,0,0,0,0);
** These are for inputting numbers
<td>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>">
<input type="text" id="inputs" name="SampleUP" value="<?php $Students_C1[0]; ?>" placeholder="<?php echo $Students_C1[0] ?>">
<input type="hidden" name="UpdateC1" >
</form>
</td>
<td>
<form action="<?php echo $_SERVER['PHP_SELF']; ?>">
<input type="text" id="inputs" name="SampleUPs" value="<?php $Students_C2[0]; ?>" placeholder="<?php echo $Students_C1[1] ?>">
<input type="hidden" name="UpdateC2" >
</form>
** And these are for updating the php array after i input those numbers
<?php
if( isset($_GET['UpdateC1']) )
{
$val1 = htmlentities($_GET['SampleUP']);
$Students_C1[0]=$val1;
}
else{}
if( isset($_GET['UpdateC2']) )
{
$val2 = htmlentities($_GET['SampleUPs']);
$Students_C2[0]=$val2;
}
else{}
?>
The flow should be if i input a number in C1 and C2 next to the student's name. that number should stay as i input. The problems is that after i input C2 number (After C1), both of the numbers reset to zero, but the C1 works fine
Any Potential solution is heartly welcomed. A complete beginner in PHP
Student Grading System

Answer 1

Okay, I can't see your output but firstly both your input IDs are the same name. Then, you do not have an input type as submit instead it is hidden. So how do you submit your form then? If you do not submit it, then there is no value passing through the GET request. Your form does not have a method as well. Next is you're having two forms on one page so I'm guessing that if you have two forms then u need to enter one form and submit it first before submitting the other? I guess that's the reason why only one of it is updated. You should include your webpage output as well to make it easier to debug.