get 在 Cocoa 中有特殊含义,The word “get” has a special meaning in Cocoa: in a Cocoa
method name, it means the method returns a value via a pointer that you pass in as a parameter.
翻译过来是什么意思:就是C语言中的输出参数了。
例如:
bufferrange:(NSRange)aRange
buffer就是一个输出参数。