[OC]阅读笔记

 

【2.NSNumber；

　　可以存放整数，浮点，布尔三种类型的数值。

NSNumber *nsNumber1 = @1;
NSNumber *nsNumber2 = @2.5;
NSNumber *nsNumber3 = @YES;

 

【3.常量

//static const  类型名 变量名  = 赋值
static const NSString * STR = @"hehe";
static const NSInteger inte = 1;

 

【4.枚举

    enum OranState {
        OranStateHappy,
        OranStateSad,
        OranStateAngry,
        OranStateNothing,
    };
    typedef enum OranState OranState;//加上这一句可以直接用Oranstate来定义，而不需使用 enum Oranstate

 

【5.类别的归属判断

BOOL a,b,c,d;
UIImageView * imageView = [UIImageView alloc];
a = [imageView isKindOfClass:[UIView class]];//YES
b = [imageView isMemberOfClass:[UIView class]];//NO
c = [imageView isKindOfClass:[UIImageView class]];//YES
d = [imageView isMemberOfClass:[UIImageView class]];//YES