<?php $servername = "localhost"; $username = "root"; $password = "admin"; $dbname = "myDB"; // 创建连接 $conn = new mysqli($servername, $username, $password, $dbname); // 检测连接 if ($conn->connect_error) { die("…

public class Test { public static void main(String args[]){ //char grade = args[0].charAt(0); char grade = 'C'; switch(grade) { case 'A' : System.out.println("优秀"); break; case 'B' : case 'C' : System.out.println("良好"); break; case 'D'…

<?php echo "<h2>PHP 很有趣!</h2>"; echo "Hello world!<br>"; echo "我要学 PHP!<br>"; echo "这是一个", "字符串,", "使用了", "多个", "参数."; ?> <?php $txt1="学习…

<?php $x=10; $y=6; echo ($x + $y); // 输出16 echo '<br>'; // 换行 echo ($x - $y); // 输出4 echo '<br>'; // 换行 echo ($x * $y); // 输出60 echo '<br>'; // 换行 echo ($x / $y); // 输出1.6666666666667 echo '<br>'; // 换行 echo ($x % $y); // 输出4 ec…

<?php $txt="Hello world!"; echo $txt; ?> <?php $txt1="Hello world!"; $txt2="What a nice day!"; echo $txt1 . " " . $txt2; ?> <?php echo strlen("Hello world!"); ?> <?php echo strpos(&quo…

<?php // 区分大小写的常量名 define("GREETING", "欢迎访问 Runoob.com"); echo GREETING; // 输出 "欢迎访问 Runoob.com" echo '<br>'; echo greeting; // 输出 "greeting" ?> <?php // 不区分大小写的常量名 define("GREETING", "…

<?php if(42 == "42") { echo '1.值相等'; } echo PHP_EOL; // 换行符 if(42 === "42") { echo '2.类型相等'; } else { echo '3.不相等'; } ?> <?php echo '0 == false: '; var_dump(0 == false); echo '0 === false: '; var_dump(0 === false); echo PHP_EO…

<?php $x = "Hello world!"; echo $x; echo "<br>"; $x = 'Hello world!'; echo $x; ?> <?php $x = 5985; var_dump($x); echo "<br>"; $x = -345; // 负数 var_dump($x); echo "<br>"; $x = 0x8C; // 十六进制…

<?php $x=5; $y=6; $z=$x+$y; echo $z; ?> <?php $txt="Hello world!"; $x=5; $y=10.5; ?> <?php $x=5; // 全局变量 function myTest() { $y=10; // 局部变量 echo "<p>测试函数内变量:<p>"; echo "变量 x 为: $x"; echo "<b…

<?php for ($i=1; $i<=5; $i++) { echo "The number is " . $i . "<br>"; } ?> <?php $x=array("one","two","three"); foreach ($x as $value) { echo $value . "<br>"; } ?>…