这是你真正的做法，老派风格，充分评论解释。
<?php
//NOTE: This excercise would be slightly easier if you just used php's DomDocument class because you wouldn't
//need to waste some logic determining whether to open/close the table rows, but here it is just echoing
//out some straight html
//The example data
$data_set = array("a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
//at the very least, you'll need to know how many columns you want to format the data into...
$number_of_columns = 5;
//count the data items
$number_of_data_items=count($data_set);
//determine how many rows you'll need to display the data in the given number of columns
$num_rows=ceil($number_of_data_items/$number_of_columns);
//determine exactly how many cells it will take to display the data
$num_cells=$num_rows*$number_of_columns;
//now that we have enough info to output the table...
//init some counters
$row_count=0;
$column_count=0;
//open the table element
echo "<table border='1' cellspacing='0' cellpadding='5'>";
for($i=0;$i<$num_cells;$i++){
$column_count++;
$index = $row_count + ($num_rows * ($column_count-1) );
if( $column_count==1 ){
echo "<tr>";
}
if( $index < $number_of_data_items){
echo "<td>Item :".($index+1)."</td>"; //Display the number of the data item we are
echo "<td>".$data_set[$index]."</td>"; //Display the actual data item
echo "<td> </td>"; //Add some extra space between columns
}else{
//write empty cells if the data set doesn't completely fill the last column
echo "<td> </td>";
echo "<td> </td>";
echo "<td> </td>";
}
if($number_of_columns == $column_count){
echo "</tr>";
$row_count++;
$column_count=0;
}
}
//close the table element
echo "</table>";
?>