使用匿名闭包进行赋值

作用：隔离代码，使得代码更加整洁

例子：

let textLabel = {
Void -> UILabelin
let label = UILabel.init(frame:CGRectMake(150,80,
30,40))
label.textColor =UIColor.yellowColor()
label.text ="text"
view.addSubview(label)
return label
}()
OC:

UIView * _labelView = ({
UIView * labelView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, _midView.frame.size.width, _midView.frame.size.height)];
labelView;
});