docs: 内容

Chapter1 - iOS/1.89.md

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+# block 原理
+
+1. 解决循环引用不应该使用 weakself，而是使用 strong-weak
+```Objective-c
+__weak typeof(self) Weakself = self;
+self.block = ^ {
+    __strong typeof(Weakself) Strongself = Weakself;
+    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^ {
+        NSLog(@"%@", Strongself.name);
+    });
+};
+self.block();
+```
+
+![image-20200810214301251](/Users/lbp/Library/Application Support/typora-user-images/image-20200810214301251.png)
+
+
+
+字节对齐：k值：8的倍数。
+
+字节对齐的原因：