一、分支与循环

1. 分支

$total = 90;
switch(true){
    case $total<60:
        echo "不合格 <br>";
        break;
    case $total>60 && $total<80:
        echo "合格 <br>";
        break;
    case $total>90:
        echo "优秀 <br>";
        break;
    default:
        echo "中等 <br>";
}

2.循环

$colors = ['red', 'green', 'blue'];
$i = 0;
while ($i < count($colors)) {
    $list .= "<li>{$colors[$i]}</li>";
    // 更新条件 
    $i = $i + 1;
}
echo 'while <br>';
echo $list.'<hr>';
$colors2 = ['red', 'green', 'blue'];
for ($i = 0; $i < count($colors); $i++) {
    $list2 .= "<li>{$colors2[$i]}</li>";
}
echo 'for <br>';
echo $list2.'<hr>';

二、php模板语法与html混编

1. php模板语法

<?php
// 用二维数组来模拟数据表查询结果集
$stus = [
    ['id' => 1, 'name' => '刘备', 'course' => 'js', 'score' => 83],
    ['id' => 2, 'name' => '关羽', 'course' => 'php', 'score' => 75],
    ['id' => 3, 'name' => '张飞', 'course' => 'js', 'score' => 52],
    ['id' => 4, 'name' => '孙权', 'course' => 'php', 'score' => 88],
    ['id' => 5, 'name' => '周瑜', 'course' => 'js', 'score' => 65],
    ['id' => 6, 'name' => '孔明', 'course' => 'php', 'score' => 53],
    ['id' => 7, 'name' => '赵云', 'course' => 'js', 'score' => 63],
    ['id' => 8, 'name' => '马超', 'course' => 'js', 'score' => 77],
    ['id' => 9, 'name' => '姜维', 'course' => 'php', 'score' => 93],
    ['id' => 10, 'name' => '黄忠', 'course' => 'js', 'score' => 81],
]
    <table>
        <caption>学生成绩表</caption>
        <thead>
            <tr>
                <th>ID</th>
                <th>姓名</th>
                <th>课程</th>
                <th>成绩</th>
            </tr>
        </thead>
        <tbody>
            <!-- 这里显示的用户数据 -->
            <?php
            foreach ($stus as $stu) {
                if ($stu['course'] === 'php') {
                    echo <<< STU
                    <tr>
                        <td>{$stu['id']}</td>
                        <td>{$stu['name']}</td>
                        <td class="active">{$stu['course']}</td>
                        <td>{$stu['score']}</td>
                    </tr>
                STU;
                }
            }
            ?>
        </tbody>
    </table>
?>

批改老师：PHPz

批改状态：合格

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