brew中字符串的操作，包括字符串的连接，查找，复制等等，多中操作方式，体现应用不同接口函数，产生的不同效果，适合初学者。-brew of string operations, including the connection string, search, copy, and so on, more of operational modes, demonstration that the application of different interface function of the di

附图1-1A为GW48-CK型EDA实验开发系统的主板结构图（GW48-GK/PK型未画出，具体结构说明应该参考实物主板），该系统的实验电路结构是可控的。即可通过控制接口键SW9，使之改变连接方式以适应不同的实验需要。因而，从物理结构上看，实验板-Figure 1-1A for the GW48-CK-type EDA experimental development system board structure (GW48-GK/PK type does not draw, the speci