objective c - Can anyone provide me an example of how to sort an array by date? -

objective c - Can anyone provide me an example of how to sort an array by date? -

i have array stores events fetched via predicate; want sort them date. read have "call sortedarrayusingselector: on array, providing selector comparestartdatewithevent: method', don't know how utilize exactly. provide me example?

here's array: nsarray *events = [store eventsmatchingpredicate:predicate] thanks!

once have array, consider:

nsarray *sortedarray = [events sortedarrayusingcomparator:^nscomparisonresult(ekevent *event1, ekevent *event2) { homecoming [event1.startdate compare:event2.startdate]; }];

this sort events start date, using built-in nsdate - compare function.

the - sortedarrayusingcomparator method takes nscomparator block, defined as:

typedef nscomparisonresult (^nscomparator)(id obj1, id obj2);

you can think of block (a lambda-function) takes 2 arguments, , homecoming nscomparisonresult fellow member explains ordering of 2 given objects are. type of object depends on shoved array, in case ekevents. how sort them you; read on nscomparator more info , rules. nsarray phone call block multiple times, presenting 2 items each time, until array sorted.

now, lucky you, ekevent exposes selector knows how compare ekevents. nsarray has method, sortedarrayusingselector: can use, , tell utilize comparing selector ekevent exposes:

nsarray *sortedarray = [events sortedarrayusingselector:@selector(comparestartdatewithevent:)];

now nsarray phone call - comparestartdatewithevent: each time wants compare 2 items. if ordering want, can utilize it. otherwise, utilize comparator method above.

objective-c eventkit