那些在学习iOS开发前就应该知道的事(part 2)http://www.cocoachina.com/ios/20150611/12111.html英文原文:Things I wish I had known before starting iOS development—Part 2https://medium.com/ios-os-x-development/things-i-wish-i-had-known-before-starting-ios-development-part-2-d696eec65866