Lab2.1 - Decisions in PHP

1.发现一个单引号和双引号的小区别。

        <?php
        // put your code here
        $a = 1;
        echo '$a is a string<br/>';
        echo "$a is a number"
        ?>

看$a的颜色你也应该能猜到运行结果：

这个地方知道就行了，不用深究原因。

2.if —— elseif —— else语句

        <?php
        // put your code here
        $result = 49;
        if ($result > 79) {
            echo 'HD';
        } elseif ($result > 69) {
            echo 'D';
        } elseif ($result > 59) {
            echo 'C';
        } elseif ($result > 49) {
            echo 'P';
        } elseif ($result > 44 && $result < 50) {
            echo 'E';
        } else {

运行结果：

和咱们之前学的都差不多，就是他的标准格式不太一样，这个写完直接右键点格式就ok。

3.switch语句的用法

        $letter = 'e';
        switch ($letter) {
            case 'a':
            case 'e':
            case 'i':
            case 'o':
            case 'u':
                echo 'Letter is a vowel';
                break;
            default :
                echo 'Letter is not a vowel';
        }

和C++一样滴。

运行结果：

Lab2.2 - Loops in PHP

来看循环

        <?php
        // 当型循环
        $count = 0;
        while ($count < 5) {
            echo "Loop number $count <br/>";
            $count ++;
        }
        echo "<hr/>";
        // 直到型循环
        $count = 0;
        do {
            echo "Loop number $count <br/>";
            $count++;
        } while ($count < 5);
        echo "<hr/>";
        for ($count = 0; $count < 5; $count++) {
            echo "Loop number $count <br/>";
        }
        echo "<hr/>";
        // for 循环
        for ($count = 0; $count < 5; $count++)
            echo "Loop number $count <br/>";
        echo "<hr/>";
        for ($count = 0; $count < 5; $count++) {
            echo "*";
        }
        echo "<br/>";
        echo "<hr/>";
        // 二重for循环
        for ($i = 0; $i < 5; $i++) {
            for ($j = 0; $j < 5; $j++) {
                echo "*";
            }
            echo "<br/>";
        }
        ?>

运行结果：

和C++机会一模一样。

Lab2.3 - PHP String Functions

字符串操作函数

        <?php
        // put your code here
        $firstname = "john";
        $lastname = "smith";
        echo strlen($firstname)."<br/>"; // 输出字符串长度
        
        $firstname = ucfirst($firstname); // 把字符串首字母大写
        $lastname = ucfirst($lastname);
        echo "$firstname $lastname<br/>";
        
        $firstname = strtoupper($firstname); // 把字符串全变成大写
        $lastname = strtoupper($lastname);
        echo "$firstname $lastname<br/>";
        
        $sentence = "the qUick brOwn foX jumps over the lazy dog.";
        $sentence = strtolower($sentence);// 把字符串全变成小写
        $sentence = ucwords($sentence); // 把每个单词的首字母大写
        echo "$sentence<br/>";
        
        $address1 = "1 Page Street Melbourne";
        $address2 = str_replace(" ","-", $address1); // 把字符串中的空格用-去替换
        echo "$address2<br/>";
        ?>

运行结果：

• strlen（）输出字符串长度
• ucfirst（）把字符串首字母大写
• strtoupper（）把字符串全变成大写
• strtolower（）把字符串全变成小写
• ucwords（）把每个单词的首字母大写
• str_replace(" “,”-", $address1)把字符串变量address2中的空格用-去替换

Lab2.4 - Progress Actiivity

练习题

        <?php
        // put your code here
        $result = 59;
        $grade = "";
        if ($result > 90) {
            $grade = "A";
        } elseif ($result >= 80 && $result <= 89) {
            $grade = "B";
        } elseif ($result >= 70 && $result <= 79) {
            $grade = "C";
        } elseif ($result >= 60 && $result <= 69) {
            $grade = "D";
        } elseif ($result >= 50 && $result <= 59) {
            $grade = "E";
        } else {
            $grade = "F";
        }
        echo "Result: $result<br/>";
        echo "Grade: $grade<br/>";
        echo "<hr/>";

        for ($i = 0; $i < 8; $i++) {
            for ($j = 0; $j < 6; $j++) {
                $number = rand(1, 45);
                echo "$number ";
            }
            echo '<br/>';
        }
        ?>

运行结果：