The method retainCount is supposed to return an unsigned integer.
Why then, does [@"Hi" retainCount] return -1?
The method retainCount is supposed to return an unsigned integer. Why then, does [@Hi
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The method retainCount is supposed to return an unsigned integer.
Why then, does [@"Hi" retainCount] return -1?
The simple answer is that because
@"Hi” is a string literal, it will always be sitting around in the binary executable image, and will never “go away”, thus retain/release have no effect, and you’re seeingUINT_MAX(which looks like -1 when printed out signed eg with %d). (See Pete Kirkham’s answer about NSObjects having these semantics).Beyond this, it’s useful to know that although @”Hi” behaves like an
NSString*, it’s actually a compiler-created instance of the classCFConstantString(or possibly NSConstantString, my debugger doesn’t agree with some documentation), which wraps the literal string data and gives you the NSString* interface on it. But the compiler knows that these strings are special and can’t ever get cleaned up, so they will always have a retainCount of UINT_MAX (-1)