字符串转数组、数组转字符串（NSArray<-->NSString）

NSArray *stringArray = @[@"甲",@"已",@"丙",@"丁"];

NSString *arrrayString = [testArray componentsJoinedByString:@"-"];

NSLog输出：arrrayString

甲-已-丙-丁

NSString *string = @"甲-已-丙-丁";

NSArray*stringArray = [string componentsSeparatedByString:@"-"];

NSLog输出：stringArray

(

"\U7532",

"\U5df2",

"\U4e19",

"\U4e01"

)