Dynamic table by column

[Alcain]

THIS IS FOR HOMEWORK, so please do not give me the direct answer but maybe the logic behind it. I cannot seem to figure this out.

 

The problem: I need to generate a dynamic table by column and not by row. The user enters a score for an exam (ie 100) on an HTML page. That value is passed and I need to create 100 different entries in a table. There is also a box that allows the user to select how many columns they want the 100 entries displayed in. So instead of having 100 rows going all the way down the page, a table with 5 columns (if they choose 5) will show while still having all 100 entries in it. 

 

What I currently have is (all the way to 1, in 1 big column)

100 -> 100% (A)

99   -> 99%   (A) 

98   -> 98%   (A) 

97   -> 97%   (A) 

96   -> 96%   (A) 

95   -> 95%   (A) 

94   -> 94%   (A) 

93   -> 93%   (A) 

92   -> 92%   (A) 

91   -> 91%   (A) 

90   -> 90%   (A) 

89   -> 89%   (B) 

88   -> 88%   (B) 

87   -> 87%   (B) 

 

In essence, the table will be generated with 100 entries, still going down the page, but if the user selects 5 columns then the 100 entries needs to be broken down into 5 columns. So it should look like this 

100 -> 100% (A)     93   -> 93%   (A)    continued on till 1

99   -> 99%   (A)     92   -> 92%   (A)

98   -> 98%   (A)     91   -> 91%   (A)

97   -> 97%   (A)     90   -> 90%   (A)

96   -> 96%   (A)     89   -> 89%   (B)

95   -> 95%   (A)     88   -> 88%   (B)

94   -> 94%   (A)     87   -> 84%   (B)

 

 

$max_points is the score for the exam.

$precision is if the user wants decimals or not

$percent is the percent of the users score. 

	for ($i = $max_points; $i > 0; $i--) {
		$p = ($i / $max_points) * 100;
			if ($precision == 0)
				$percent = round($p, 0);
			else
				$percent = number_format($p, 2, '.', '');

		echo "<tr>";
		echo "<td class='points'>$i ⇒</td>";
		echo "<td class='pctGrade'>$percent%</td>";	
			if ($percent >= $a_min) 
				echo "<td class='ltrGrade'>(A)</td>";
			elseif ($percent >= $b_min)
				echo "<td class='ltrGrade'>(B)</td>";
			elseif ($percent >= $c_min)
				echo "<td class='ltrGrade'>(C)</td>";
			elseif ($percent >= $d_min)
				echo "<td class='ltrGrade'>(D)</td>";
			else
				echo "<td class='ltrGrade'>(F)</td>";
		echo "</tr>";
		echo "</th>";
	}
	echo "</table>"; 

[Barand]

A couple of simple approaches

 

1) Output each entry into a <div> with left float. Set the width of the divs to just a little less than an Nth of the page width (N= no of columns.)

 

or

 

2) Put the entries into an array then use array_chunk() to give a chunk for each row. Loop through the chunks outputting each into a row.

Edited September 19, 2017 by Barand

[dalecosp]

And a 3rd approach: implement a counter and check its modulus against the desired number of columns ...

Older-school, hackish, should work though.

[Sepodati]

Focusing on the math here, instead of counting from 100 to 1, you're going to count in two loops, based on the $columns value the user wants and the numbers of $rows (100/$columns) that are necessary.

 

So if you have 3 columns, you'll have 33.333 rows, which you round up to 34 rows. With 5 columns, you have 20 rows. Some of the final cells in the final row may be empty, since the columns may not evenly divide into 100.

 

Your outer "row" loop ($r) is going to count from 100 down to (100-$rows).

 

Your inner "column" loop ($c) is going to count from 0 to ($columns - 1).

 

For each column loop, you output the values related to ($r - ($c * $rows)). So the first time, you're showing (100 - (0 * 34)) = 100 in the first cell, (100 - (1 * 34)) = 66 in the second column and (100 - (2 * 34)) = 32 in the third column. You'll notice that should be 33, so you'll need to play with the math here as you sort this out. Probably need a +1 in some places and remember the rounded-up and rounded-down $rows value.

 

If ($r - ($c * $rows) < 1, then output a blank cell.

 

Combine those two loops and you output 34 * 3 cells, with some of the last ones being blank, when the user requests 3 columns.

 

There are probably much easier ways to do this with some fancy CSS or something, but from a purely math standpoint in determining rows & columns from arbitrary user input, that's how I'd do it.

 

-John

Edited September 19, 2017 by Sepodati

[Alcain]

Thank you, everyone, for the input. I found Sepodati's answer to be the easiest to implement. I have the code working perfectly now.

[Sepodati]

Sounds like I gave too many details, then!

Edited September 19, 2017 by Sepodati