完整路径

NSString* index=@"/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents/1543976290.wav";

对路径截取的9种操作

NSLog(@"%@",[index lastPathComponent]);
输出：1543976290.wav

NSLog(@"%@",[index stringByDeletingLastPathComponent]);
输出：/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents

NSLog(@"%@",[index pathExtension]);
输出：wav

NSLog(@"%@",[index stringByDeletingPathExtension]);
输出：/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents/1543976290

NSLog(@"%@",[index stringByAbbreviatingWithTildeInPath]);
输出：~/Documents/1543976290.wav

NSLog(@"%@",[index stringByExpandingTildeInPath]);
输出：/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents/1543976290.wav

NSLog(@"%@",[index stringByStandardizingPath]);
输出：/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents/1543976290.wav

NSLog(@"%@",[index stringByResolvingSymlinksInPath]);
输出：/var/mobile/Containers/Data/Application/45471D33-E611-499D-AFA1-856880F47549/Documents/1543976290.wav

NSLog(@"%@",[[index lastPathComponent] stringByDeletingPathExtension]);
输出：1543976290