UIButton tag is nil

Question

As far as I know the "tag" field in UIView is integer. Why one of my UIButtons has "nil" value in it's tag?

(lldb) po [button_one tag]
nil

I've set the tag 0 in designer, but still returns nil tag in code.

Answer 1

po means 'print object'. An integer isn't an object. And nil would be equal to an integer value of zero.

So, in lldb you should be using p to print the integer value. And it is probably correct.

Answer 2

My output is slightly different, but the point is, trying to print object on an integer (as Wain says) results in nil if the integer is 0 and an error if it is non-zero. (but in this case lldb still gives the p (int) value)

(lldb) po 0
$0 = 0 <nil>
(lldb) po nil
$1 = 0x00000000 <nil>
(lldb) po button.tag
$2 = 0 <nil>
(lldb) p (int)button.tag
(int) $3 = 0

Set the tag to 1

(lldb) po button.tag
$4 = 1 [no Objective-C description available]
(lldb) p (int)button.tag
(int) $5 = 1