arrays - How to swap two dates in swift -

trying swap 2 dates in swift. gives me error saying:

cannot subscript value of type '[mission]' index of type 'int'

func sort (mission: [mission]) -> bool {     (var = 0; < mission.count; i++) {         println(mission[i].createdat)         if mission[i].createdat.timeintervalsince1970 > mission[i+1].createdat.timeintervalsince1970 {             var temp = mission[i]             mission[i] = mission[i+1]             mission[i+1] = temp         }     }     println()     return true } 

this function named sort, doesn't sort array. if you're trying sort array, should use builtin sort function:

missions.sort { $0.createdat.timeintervalsince1970 > $1.createdat.timeintervalsince1970 } 

the function you've written it, compilable, cause fatalerror because try access out-of-bounds index. i goes 1 count - 1 , try mission[i+1]. fix should change range of loop stop @ count - 2.

the error compiler giving caused fact function parameters immutable default, assignments aren't possible. if want changes visible outside function, you'll need mark argument inout.

further, swap should use swift's builtin swap function instead of implementing yourself. putting of together:

func sort(inout mission: [mission]) -> bool {     in 0..<mission.count-1 {         println(mission[i].createdat)         if mission[i].createdat.timeintervalsince1970 > mission[i+1].createdat.timeintervalsince1970 {             swap(&mission[i], &mission[i+1])         }     }     println()     return true }