这一行代码也会专门处理null值，它将null值转换为一个空字符串以避免后面的处理出现问题。

This line also traps for a null value and converts it to an empty string to prevent problems during later processing.

youdao

这一行代码也会专门处理null值，它将null值转换为一个空字符串以避免后面的处理出现问题。

This line also traps for a null value and converts it to an empty string to prevent problems during later processing.

youdao