Collection
Collection
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
<?php
$n = 1;
while($n<=9){
$i = 1;
while($i<=$n){
echo "$i"."x"."$n=".($i*$n)." ";
$i++;
}
echo "<br />";
$n++;
}