set array empty

Question

I have a clear history button which clears the data in plist. Now, loading is fine; I load it to an array.

Can I just use:

self.dataClear = NULL;

and save back the array to plist to clear it? So that I can use

if([self.dataClear count] == 0)//if plist is empty

to check?

ig2r · Accepted Answer · 2010-08-22 18:33:03Z

19

You'd probably be better off using a NSMutableArray and calling removeAllObjects on that instead of NULLing it out; otherwise, there won't be any object there to respond to your count message, since there's a conceptual difference between "empty array" and "no array at all".

answered Aug 22, 2010 at 18:33

ig2r

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4 Comments

Georg Fritzsche Over a year ago

Although a mutable array most likely fits better, sending messages to nil is fine in this case - see e.g. here.

ig2r Over a year ago

Indeed, though I wanted to stress that distinction between nil and empty, since I consider count working as expected here somewhat of a fringe case. Nevertheless, your point is correct.

Stefan Over a year ago

i set to nil, it doesn't work, use removeALlobjects and it works.

James Over a year ago

Thanks, exactly what I needed to do a table refresh.

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