分支、循环、php模板语法与html混编实例演示 -

分支实例演示

<?php
// 流程控制：分支
// 1.单分支
$age = 10;
if($age >= 18){
    echo '恭喜你，成年人';
}
// 2.双分支
$age = 10;
if($age >= 18){
    echo '恭喜你，成年人';
}else{
    echo '小学生，好好学习';
}
echo '<hr>';
// 分支只有一行代码，可以不写大括号
$age = 30;
if($age >= 18)
    echo '恭喜你，成年人';
else
    echo '小学生，好好学习';
echo '<hr>';
// 3.多分支
$age = 100;
if($age >= 18 && $age < 40 ){
    echo "{$age}岁，改结婚了";
}else if($age >= 40 ) {
    echo "{$age}岁，好好锻炼身体";
}else{
    echo '小学生，好好学习';
}
echo '<hr>';
// 4.多分支的语法糖：switch
$age = 25;
switch(true)
{
    case $age >= 18 && $age < 40 ;
        echo "{$age}岁，改结婚了";
        break;
    case $age >= 40 ;
        echo "{$age}岁，好好锻炼身体";
        break;
    default:
        echo '小学生，好好学习';
}

循环实例演示

<?php
// 流程控制：循环
$car = ['BMW','volvo','haval'];
print_r($car);
echo '<br>';
echo $car[2] . '<br>';
// 1.初始化循环变量，用索引当循环变量
$i =0;
// 2.循环条件：
// 数组长度 = 最大索引+1
// echo count($car);
if($i < count($car))
{
    echo $car[$i] . '<br>';
}
// 3.更新循环条件
$i =$i+1;
if($i < count($car))
{
    echo $car[$i] . '<br>';
}
echo '<hr>';
// 简化循环改写：while()
$i = 0;
while($i < count($car))
{
    echo $car[$i] . '<br>';
    $i =$i+1;
}
// 案例列表
$list = '<ul style="border:1px solid;background:cyan;">';
$i = 0;
while($i < count($car))
{
    $list .= "<li>{$car[$i]}</li>";
    $i =$i+1;
}
$list .= '</ul>';
echo $list;
echo '<hr>';
$list = '<ul style="border:1px solid;background:red;">';
$i = 0;
do{
    $list .= "<li>{$car[$i]}</li>";
    $i =$i+1;
}while($i > count($car));
$list .= '</ul>';
echo $list;
// for改写
$list = '<ul style="border:1px solid;background:yellow;">';
for($i =0;$i < count($car);$i++)
{
    $list .= "<li>{$car[$i]}</li>";
}
$list .= '</ul>';
echo $list;
// 中断:break
$list = '<ul style="border:1px solid;background:violet;">';
for($i =0;$i < count($car);$i++)
{
    if($i >1) break;
    $list .= "<li>{$car[$i]}</li>";
}
$list .= '</ul>';
echo $list;
// 跳过某次循环:continue;
$list = '<ul style="border:1px solid;background:violet;">';
for($i =0;$i < count($car);$i++)
{
    if($i === 1) continue;
    $list .= "<li>{$car[$i]}</li>";
}
$list .= '</ul>';
echo $list;

php模板语法与html混编实例演示

<?php
$users =[
    ['id'=>'1','name'=>'李白','course' =>'php','gender'=>0,'score'=>60],
    ['id'=>'2','name'=>'杜甫','course' =>'mysql','gender'=>1,'score'=>30],
    ['id'=>'3','name'=>'韩愈','course' =>'js','gender'=>0,'score'=>90],
    ['id'=>'4','name'=>'杜牧','course' =>'php','gender'=>1,'score'=>80],
];
?>
<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>php模板语法</title>
</head>
<body>
   <table border="1" width ="500" cellspacing ="0" cellpadding="3" aling ="center">
       <caption>用户信息表</caption>
       <thead>
           <tr bgcolor = "#ccc">
               <th>id</th>
               <th>姓名</th>
               <th>课程</th>
               <th>性别</th>
               <th>成绩</th>
           </tr>
       </thead>
       <!-- 遍历 -->
       <tbody align="center">
           <?php foreach($users as $user) : ?>
            <!-- “{”  => 冒号加php结束标记 -->
            <!-- <tr>
                <td><?php echo $user['id'] ?></td>
                <td><?php echo $user['name'] ?></td>
                <td><?php echo $user['course'] ?></td>
                <td><?php echo $user['gender']?'女' : '男' ?></td>
                <td><?php echo $user['score'] ?></td>
            </tr> -->
            <!-- 仅输出成绩大于60分的 -->
            <!-- <?php if ($user['score'] >= 60) : ?>
                <tr>
                    <td><?php echo $user['id'] ?></td>
                    <td><?php echo $user['name'] ?></td>
                    <td><?php echo $user['course'] ?></td>
                    <td><?php echo $user['gender']?'女' : '男' ?></td>
                    <td><?php echo $user['score'] ?></td>
                </tr>
            <?php endif ?> -->
            <!-- 输出全部，低于60分的标红 -->
            <tr>
                <td><?php echo $user['id'] ?></td>
                <td><?php echo $user['name'] ?></td>
                <td><?php echo $user['course'] ?></td>
                <td><?php echo $user['gender']?'女' : '男' ?></td>
                <?php $color = $user['score'] < 60 ?'style="color: red;"' : '' ?>
                <td <?php echo $color  ?>><?php echo $user['score'] ?></td>
            </tr>
            <?php endforeach ?> 
       </tbody>
   </table> 
</body>
</html>