New Objective-c Literals in 4.4

问题

I can write @42, which creates an NSNumber with int value 42. Can I do this with a variable, like @someIntVar? Obviously I tried it and it doesn't work (which sucks because then I have to go through [NSNumber numberWithInt:someIntVar]). Is it possible with a slightly different syntax?

回答1:

I strongly suggest you read the official clang documentation on the matter: http://clang.llvm.org/docs/ObjectiveCLiterals.html

But, to box a variable, or any expression, you can use parentheses:

 id num = @(someIntVar);

来源：https://stackoverflow.com/questions/12120153/new-objective-c-literals-in-4-4