iphone - How to check null value of object in decision statement for Objective C -


i getting object value server null value when nslog object.i want identify in if-else decision statement. how can check because nil have reference unknown object not means null.and can't compare 0 too.

how can identify value null, have crash on point.i have tried @try - @catch block gone in vain.

any suggestion problem.

as others have pointed out, there many kinds of "null" under cocoa/objective c. 1 further thing note [object iskindofclass:[nsnull class]] pointlessly complex since [nsnull null] documented singleton can check pointer equality. see topics cocoa: using null

so use :-

  if (title == (id)[nsnull null] || title.length == 0 ) title = @"something";

note how can use fact if title nil, title.length return 0/nil/false, ie 0 in case, not have special case it. people new objective c have trouble getting used to, coming form other languages messages/method calls nil crash.

if want in detail difference between nil, nil , null, can check article what difference between nil, nil , null.


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