...ome/None), not the value itself (T). So john isn't an instance of Person, and it doesn't have an apartment member: john.apartment // 'Person?' does not have a member named 'apartment' The actual Person value can be unwrapped in various ways: "forced unwrapping": john! (gives the Person value i...

... of the negative values of a, since (a % b) is a negative value between -b and 0, (a % b + b) is necessarily lower than b and positive. The last modulo is there in case a was positive to begin with, since if a is positive (a % b + b) would become larger than b. Therefore, (a % b + b) % b turns it in...

...e navigation bar. Set the delegate of the toolbar to your view controller, and return UIBarPositionTopAttached in positionForBar:. You can see in the store app, if you perform an interactive pop gesture, that the segment bar does not move the same as the navigation bar. That's because they are not t...

What is the difference between var_dump() and print_r() in terms of spitting out an array as string? 12 Answers ...

... this subject, read various articles about this header, its use in Heroku, and projects based on Django. 4 Answers ...

Do you think there is a big difference in for...in and for loops? What kind of "for" do you prefer to use and why? 23 Answe...

... incoming isn't quite a direct mapping in git because you can (and I often do) have multiple repos you're pulling from, and each repo has multiple branches. If there were an equivalent of hg's incoming command, it'd probably be this: git fetch && git log ..origin/master That ...

How to get document height and width in pure javascript i.e without using jquery . I know about $(document).height() and $(document).width() , but I want to do this in javascript . ...

I am working through setting up a http server using node.js and engine. However, I keep running into issues that I have little information on how to resolve I would appreciate some help solving this please. ...

I need to read, write and create an INI file with Python3. 6 Answers 6 ...