阿神2017-04-22 09:01:56
NS is the abbreviation of NeXTSTEP. NeXTSTEP is a company founded by Steve Jobs after he was kicked out of Apple. It was later brought back to Apple, and these codes were brought into Apple. There is no package or domain name space in obj c, so we rely on prefixes to distinguish them.
ringa_lee2017-04-22 09:01:56
An anti-crash mechanism of Objective-C, the capital letter before the class name is used as a prefix for distinction
