分支循环,php 模板语法与 html 混编技巧

一.分支循环

分支循环

<?php
//单分支
$age = 20;
if ($age >= 18) {
   echo "用户已成年<br>";
}
//双分支
$age = 15;
if ($age >= 18) {
   echo "用户已成年<br>";
} else {
   echo "用户未成年<br>";
}
//三元表达式
$age = 25;
echo ($age >= 15) ? "用户已成年<br>" : "用户未成年<br>";
//多分支
$age = 35;
if ($age <= 18) {
   echo "用户未成年<br>";
} else if ($age >= 18 && $age <= 30) {
   echo "用户已成年,每天适当游戏时间<br>";
} else {
   echo "用户已成年,合理安排游戏时间<br>";
};
//多分支的语法糖
$age = 28;
switch (true) {
   case $age <= 18:
      "用户未成年<br>";
      break;
   case $age >= 18 && $age <= 30:
      echo "用户已成年,每天适当游戏时间<br>";
      break;
   default:
      echo "用户已成年,合理安排游戏时间<br>";
      break;
}
echo "<hr>";
//循环
$colors = ['red', 'green', 'blue'];
//初始化循环变量
$i = 0;
//设置循环条件
while ($i < count($colors)) {
   echo $colors[$i] . "<br>";
   //更新循环条件
   $i = $i + 1;
}
//循环语法糖for
for ($i = 0; $i < count($colors); $i++) {
   echo $colors[$i] . "<br>";
}
echo "<hr>";
//中断或跳过某次循环
$colors = ['red', 'green', 'blue', 'red', 'green', 'blue'];
for ($i = 0; $i < count($colors); $i++) {
   //只输出前五个
   if ($i > 4) break;
   //跳过第二个
   if ($i === 1) continue;
   echo $colors[$i] . "<br>";
}

二.php 模板语法与 html 混编技巧

php模板语法与html混编技巧

<?php
$stus = [
   ['id' => 1, 'name' => '刘备', 'course' => 'js', 'score' => 83],
   ['id' => 2, 'name' => '关羽', 'course' => 'php', 'score' => 75],
   ['id' => 3, 'name' => '张飞', 'course' => 'js', 'score' => 52],
   ['id' => 4, 'name' => '孙权', 'course' => 'php', 'score' => 88],
   ['id' => 5, 'name' => '周瑜', 'course' => 'js', 'score' => 65],
   ['id' => 6, 'name' => '孔明', 'course' => 'php', 'score' => 53],
   ['id' => 7, 'name' => '赵云', 'course' => 'js', 'score' => 63],
   ['id' => 8, 'name' => '马超', 'course' => 'js', 'score' => 77],
   ['id' => 9, 'name' => '姜维', 'course' => 'php', 'score' => 93],
   ['id' => 10, 'name' => '黄忠', 'course' => 'js', 'score' => 81],
]
?>
<!DOCTYPE html>
<html lang="en">
<head>
   <meta charset="UTF-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, initial-scale=1.0">
   <title>php模板语法与html混编技巧</title>
   <style>
      table {
         border-collapse: collapse;
         border: 1px solid black;
         text-align: center;
         width: 400px;
         margin: 0 auto;
      }
      table th,
      table td {
         border: 1px solid black;
      }
      .js_course {
         background-color: darkcyan;
      }
      .php_course {
         background-color: burlywood;
      }
      .un_score {
         background-color: red;
         color: white;
      }
   </style>
</head>
<body>
   <table>
      <caption>学习成绩表</caption>
      <thead>
         <th>ID</th>
         <th>姓名</th>
         <th>课程</th>
         <th>分数</th>
      </thead>
      <tbody>
         <!-- 数组的遍历,foreach(数组 as 键名 =>值){...} -->
         <?php foreach ($stus as $stu) : ?>
            <tr>
               <!-- <?php echo "123" ?> 简化为 <?= "123" ?> -->
               <td><?= $stu["id"] ?></td>
               <td><?= $stu["name"] ?></td>
               <?php $course_type = ($stu["course"] === "js") ? "js_course" : "php_course" ?>
               <td class=<?= $course_type ?>><?= $stu["course"] ?></td>
               <?php $score_type = ($stu["score"] < 60) ? "un_score" : "" ?>
               <td class=<?= $score_type ?>><?= $stu["score"] ?></td>
            </tr>
         <?php endforeach ?>
      </tbody>
   </table>
</body>
</html>