added some interview questions

youngshook · youngshook · commit 096857666796 · 2015-03-09T22:21:31.000+08:00
* &#22914;&#20309;&#20026;Class&#23450;&#20041;&#19968;&#20010;&#23545;&#22806;&#21482;&#35835;&#23545;&#20869;&#21487;&#35835;&#20889;&#30340;&#23646;&#24615;?
* How to avoid retain cycle when using Blocks?
* Difference between Category and Class Extension? 
* What is a meta-class in Objective-C?
diff --git a/README.md b/README.md
@@ -38,6 +38,10 @@
 * &#22914;&#20309;&#35753; Category &#25903;&#25345;&#23646;&#24615;&#65311;
 * `NSOperation` &#30456;&#27604;&#20110; GCD &#26377;&#21738;&#20123;&#20248;&#21183;&#65311;
 * `strong` / `weak` / `unsafe_unretained` &#30340;&#21306;&#21035;&#65311;
+* &#22914;&#20309;&#20026;Class&#23450;&#20041;&#19968;&#20010;&#23545;&#22806;&#21482;&#35835;&#23545;&#20869;&#21487;&#35835;&#20889;&#30340;&#23646;&#24615;?
+* How to avoid retain cycle when using Blocks?
+* Difference between Category and Class Extension? 
+* What is a meta-class in Objective-C?
 * `UIView` &#21644; `CALayer` &#20043;&#38388;&#30340;&#20851;&#31995;&#65311;
 * &#20160;&#20040;&#26102;&#20505;&#20250;&#21457;&#29983;&#12300;&#38544;&#24335;&#21160;&#30011;&#12301;&#65311;
 * &#22914;&#20309;&#22788;&#29702;&#24322;&#27493;&#30340;&#32593;&#32476;&#35831;&#27714;&#65311;

-Original file line number
+Diff line change
 * 如何让 Category 支持属性？
 * `NSOperation` 相比于 GCD 有哪些优势？
 * `strong` / `weak` / `unsafe_unretained` 的区别？
 +* 如何为Class定义一个对外只读对内可读写的属性?
 +* How to avoid retain cycle when using Blocks?
 +* Difference between Category and Class Extension?
 +* What is a meta-class in Objective-C?
 * `UIView` 和 `CALayer` 之间的关系？
 * 什么时候会发生「隐式动画」？
 * 如何处理异步的网络请求？