99乘法表

一、for循环

$num=1;
for ($a=1;$a<=9;$a++){
    for ($b=1;$b<=$a;$b++)
        echo "$a"."x"."$b"."=".$a*$b." ";
    echo "<br/>";
}

二、while循环

$a=1;
while ($a<=9){
    $b=1;
    while ($b<=$a){
        echo "{$a}x{$b}=".($a*$b)." "." ";
        $b++;
    }
    echo "<br/>";
    $a++;
}

三、do while循环

$a=1;
do {
    $b=1;
    do {
        echo "{$b}x{$a}=".($b*$a)." ";
        $b++;
    } while($b<=$a);
    echo "<br/>";
    $a++;
} while($a<=9);

四、表格展示

echo "<table width='1' border='1'>";
for($j=1;$j<=9;$j++) {
    echo "<tr>";
    for ($i = 1; $i <= $j; $i++) {
        echo "<td>{$i}*{$j}=" . ($i * $j) . "</td>";
    }
    echo "</tr>";
}
echo "</table>";