Basic application of for loop in PHP: Nine-Nine Multiplication Table

The code is as follows:

<?php 
/* 
*打印乘法口绝表 
*/ 
echo "九灵九乘法口绝表<br><br><br>"; 
echo "<table>"; 
for($i=1;$i<=9;$i++){ 
echo "<tr>"; 
for($j=1;$j<=$i;$j++){ 
echo "<td>".$j."*".$i."=".($j*$i)."</td>"; 
} 
echo "</tr>"; 
} 
echo "</table>"; 
echo "<br><br><br><br><br><br>"; 
echo "<table>"; 
for($i=1;$i<=9;$i++){ 
echo "<tr>"; 
for($j=$i;$j<=9;$j++){ 
echo "<td>".$i."*".$j."=".($j*$i)."</td>"; 
} 
echo "</tr>"; 
} 
echo "</table>"; 
?>