If Else statements by inputted form name [duplicate] - php

Question

This question already has answers here:
php: check if an array has duplicates
(17 answers)
Closed 7 months ago.
is there a way to write an if else statement by the input field name?
I have a loop that dynamically creates 9 input field,
The loop
for($i=0; $i<($n*$n); $i++){
echo "<tr>";
for($j=0; $j<($n*$n); $j++){
$number = "column".$i.$j;
if($i%$n==0 && $j%$n==0 && $j!==0 && $i!==0){
echo "<td><input class='field' type='text' name=$number value=$_POST[$number]></td>";
}
and the output is this.
<input class="field" type="text" name="column00" value="1">
<input class="field" type="text" name="column01" value="2">
<input class="field" type="text" name="column02" value="1">
.....
<input class="field" type="text" name="column09" value="3">
So what I am trying to do is, that if there is a inputed number on row 1 to 9 that is equal to another number in row 1 to 9 it will echo out that there more than one number thats equal to each other.
I tried something like this but it wouldn't work.
if($number==$number){
echo = "equal number in the same row";
}

Answer 1

Make an array of all the inputs from a row. Then do:
$unique = array_unique($row_values);
if (count($unique) != count($row_values)) {
echo "No duplicate numbers in a row!";
}
Do the same thing for each column.

Answer 2

Use field names in this form:
<input name="number[<row>][<column>]" ...
So, for instance:
<input name="number[0][0]" value="1" />
<input name="number[0][1]" value="2" />
<input name="number[0][2]" value="5" />
<input name="number[0][3]" value="3" />
...
<input name="number[1][0]" value="4" />
<input name="number[1][1]" value="9" />
When posted, you will receive a two-dimensional array:
[[1, 2, 5, 3, ...], [4, 9, ...]]
Now it basically becomes an array problem you have to solve for:
All rows and columns
Rows and columns within each grid
To help you find the value that occurs multiple times in an array:
$multiples = array_filter(array_count_values($arr), function($freq) {
return $freq > 1;
});
// outputs a non-empty array with the numbers that occur more than once.
print_r(array_keys($multiples));