进入学习php语言状态。昨日看了一天视频。才能够把这个小口诀表实现。好难啊。

里面有个口诀表的函数、        

";
for ($a=1;$a<=9;$a++){ //循环输出a a默认值是1 a的值不会大于9 且不断加一
                           
        for ($b=1;$b<=$a;$b++){//{b默认值是1  且b值不能大于a值 也就是九  加一运算
/*一开始a等于1的，满足$a<=9  往下运行，b=1，满足$b<=$a，输出echo "$b x $a = $c"  ; 当b加一运算后，，不能满足$b<=$a，跳出循环，运行echo "
"  回到$a 循环，a加一 运算  此时a=2  满足$a<=9  。往下运行，b=1，满足$b<=$a，输出echo "$b x $a = $c"，输出后 b加一运算了  等于2还是满足$b<=$a ，继续往下运行，b=2，满足$b<=$a，输出echo "$b x $a = $c"
*/
        $c=$a*$b;           //定义变量C的值
    echo "$b x $a = $c"  ; //输出变量b x 变量a 等于变量c 
    echo "              ";  //空格
        }
                           
    echo "
";  //回车
    }
/*以上几句代码实现99乘法表
1 x 1 = 1
1 x 2 = 2 2 x 2 = 4
1 x 3 = 3 2 x 3 = 6 3 x 3 = 9
1 x 4 = 4 2 x 4 = 8 3 x 4 = 12 4 x 4 = 16
1 x 5 = 5 2 x 5 = 10 3 x 5 = 15 4 x 5 = 20 5 x 5 = 25
1 x 6 = 6 2 x 6 = 12 3 x 6 = 18 4 x 6 = 24 5 x 6 = 30 6 x 6 = 36
1 x 7 = 7 2 x 7 = 14 3 x 7 = 21 4 x 7 = 28 5 x 7 = 35 6 x 7 = 42 7 x 7 = 49
1 x 8 = 8 2 x 8 = 16 3 x 8 = 24 4 x 8 = 32 5 x 8 = 40 6 x 8 = 48 7 x 8 = 56 8 x 8 = 64
1 x 9 = 9 2 x 9 = 18 3 x 9 = 27 4 x 9 = 36 5 x 9 = 45 6 x 9 = 54 7 x 9 = 63 8 x 9 = 72 9 x 9 = 81
*/
?>
";
for ($x=9;$x>=1;$x-- ){
  for ($y=9;$y>=$x;$y--){
      $z=$x*$y;
      echo "$y X $x =$z";
      echo "         ";
  }
   echo "
";
}
 ?>
";
function cheng($a,$b=9){ 
                                                    //a是一个乘数；b是另一个乘数，初始值是9
    for ($x=$a;$x<=$b;$x++){
                               
        for ($y=1;$y<=$x;$y++){
            $z=$y*$x;
            echo "$y X $x =$z";
            echo "  ";
        }
    echo "
";
    }
}
echo cheng(3,7);  调用了函数
echo "=============================================
";
echo cheng(1 );
//**********乘法表函数*********
?>