0806作业

一、给定一个数组$arr = [23,3,45,6,78,8,34],筛选其偶数成员组成新的数组返回，请封装函数。

<?php
$arr = [23,1,25,7,23,7,12];
$arr7=[];
function arr($arr,$arr7)
{
  for ($i = 0; $i <count($arr);$i++){
      //print($arr[$i]);
      if(($arr[$i]%2)==1){
          array_push($arr7,$arr[$i]);
      }
      echo "<br>";
  }
  print_r($arr7);
}
arr($arr,$arr7);
?>

二、尝试实现简单的计算器功能，语言不限制。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>计算器</title>
</head>
<body>
<?php
    error_reporting(E_ALL & ~E_NOTICE);
    if(isset($_POST['sub'])):
        if($_POST['opt'] == '/' && $_POST['num2'] == 0 || $_POST['opt'] == '%' && $_POST['num2'] == 0) $mess = "<span style='color:red;'>oops~除数不能为0</span>";
    endif;
?>
    <h1>计算器</h1>
    <table>
        <form action="" method="post">
            <tr>
                <td>
                    <input type="number" name="num1" required  value="<?=$_POST['num1']?>">
                </td>
                <td>
                    <select name="opt">
                        <option value="+" <?=$_POST["opt"] == "+" ? "selected" : "" ?> >+</option>
                        <option value="-" <?=$_POST["opt"] == "-" ? "selected" : "" ?>>-</option>
                        <option value="*" <?= $_POST["opt"] == "*" ? "selected" : "" ?>>*</option>
                        <option value="/" <?= $_POST["opt"] == "/" ? "selected" : "" ?>>/</option>
                        <option value="%" <?= $_POST["opt"] == "%" ? "selected" : "" ?>>%</option>
                    </select>
                </td>
                <td>
                    <input type="number" name="num2" required value="<?=$_POST['num2']?>" >
                </td>
                <td>
                        <input type="submit" name="sub" value="计算">
                </td>
            </tr>
        </form>
        <?php
        if(!$mess && isset($_POST['sub']) ):
            switch($_POST['opt']):
                case "+":
                    $sum = (int)$_POST['num1'] + (int)$_POST['num2'];break;
                case "-":
                    $sum = (int)$_POST['num1'] - (int)$_POST['num2'];break;
                case "*":
                    $sum = (int)$_POST['num1'] * (int)$_POST['num2'];break;
                case "/":
                    $sum = (int)$_POST['num1'] / (int)$_POST['num2'];break;
                case "%":
                    $sum = (int)$_POST['num1'] % (int)$_POST['num2'];break;
            endswitch;
            $res = "计算结果:{$_POST['num1']} {$_POST['opt']} {$_POST['num2']} = {$sum}";
            echo "<span style='color:green;'>{$res}</span>";
        else:
            echo $mess;
        endif;
        ?>
    </table>
</body>
</html>