4.27 定界符与运算流程控制

1. 九宫格
   

代码

echo <<<EOF
      <table border="1" cellspacing="0" cellspadding="0">
      <tr>
      <td bgcolor="red">1</td>
      <td bgcolor="yellow">2</td>
      <td bgcolor="blue">3</td>
      </tr>
      <tr>
      <td bgcolor="green">4</td>
      <td bgcolor="orange">5</td>
      <td bgcolor="pink">6</td>
      </tr>
      <tr>
       <td bgcolor="whtie">7</td>
      <td bgcolor="violet">8</td>
      <td bgcolor="coral">9</td>
      </tr>
      </table>
EOF;

---

2.简易计算器

代码

echo <<<EOF
    <form action="" method="get">
    <input type="number" name="num1">
    <select name="select">
    <option value="+">+</option>
    <option value="-">-</option>
    <option value="*">*</option>
    <option value="/">/</option>
    <option value="%">%</option>
    </select>
    <input type="number" name="num2">
    <button type="submit">=</button>
    </form>
EOF;
$num1 = (int)$_GET["num1"];
$num2 = (int)$_GET["num2"];
$select = $_GET["select"];
$new;
switch ($select) {
    case "+":
        echo $new = $num1 + $num2;
        break;
    case "-":
        echo $new = $num1 - $num2;
        break;
    case"*":
        echo $new = $num1 * $num2;
        break;
    case"/":
        if ($num2 == 0) {
            echo "<script>alert('0不能作为除数')</script>";
        }
        else{
            echo $new = $num1 / $num2;
        }
        break;
    case"%":
        if ($num2 == 0) {
            echo "<script>alert('0不能作为除数')</script>";
        }
        else{
            echo $new = $num1 % $num2;
        }
        break;
}