Switch to the IDE and place the cursor in the first line of index.php, just about to include the class file.

切换到IDE，将游标放在index . php的第一行，就在包含类文件的地方。

youdao

In my example, the first half of the program is simply a switch to allow manual selection of the backend to use from the command-line.

在我的示例中，该程序的上半部分完全是实现一个switch，允许从命令行手工选择要使用的后端。

youdao

The switch has first contact connected to first data line, second contact connected to second data line, and switch control line.

开关具有连接到第一数据线的第一触点和连接到第二数据线的第二触点、以及开关控制线路。

youdao