iOS分享世界MG的iOS经验总结

OC基础 — NSNumber

2016-08-06  本文已影响245人  Mg明明就是你

| 项目 | 简介 |
| : | : |
| MGDS_Swif | 逗视视频直播 |
| MGMiaoBo | 喵播视频直播 |
| MGDYZB | 斗鱼视频直播 |
| MGDemo | n多小功能合集 |
| MGBaisi | 高度仿写百思 |
| MGSinaWeibo | 高度仿写Sina |
| MGLoveFreshBeen | 一款电商App |
| MGWeChat | 小部分实现微信功能 |
| MGTrasitionPractice | 自定义转场练习 |
| DBFMDemo | 豆瓣电台 |
| MGPlayer | 一个播放视频的Demo |
| MGCollectionView | 环形图片排布以及花瓣形排布 |
| MGPuBuLiuDemo | 瀑布流--商品展 |
| MGSlideViewDemo | 一个简单点的侧滑效果,仿QQ侧滑 |
| MyResume | 一个展示自己个人简历的Demo |
| GoodBookDemo | 好书 |

Snip20161026_15.png
Snip20161026_16.png
Snip20161026_35.png 逗视介绍1.gif
逗视介绍2.gif

1.NSNumber基本使用

-(void) test{
       // 封装基本数据类型(int,float,double,char,BOOL)
       int basicInt = 6;
       float basicFloat = 3.14;
       double basicDouble = 0.85;
       char basicChar = 'c';
       BOOL basicBool = 1;
 
        // 创建int型对象
        NSNumber *objectInt = [NSNumber numberWithInt:basicInt];
        NSLog(@"objectInt = %@", objectInt);
        NSLog(@"还原后:%d", [objectInt intValue]);
 
        // 创建float型对象
        NSNumber *objectFloat = [NSNumber                                 numberWithFloat:basicFloat];
        NSLog(@"objectFloat = %@", objectFloat);
        NSLog(@"还原后:%f", [objectFloat floatValue]);
 
        // 创建double型对象
        NSNumber *objectDouble = [NSNumber numberWithDouble:basicDouble];
        NSLog(@"objectDouble = %@", objectDouble);
        NSLog(@"还原后:%f", [objectDouble doubleValue]);
 
       // 创建char型对象
       NSNumber *objectChar = [NSNumber    numberWithChar:basicChar];
       NSLog(@"objectChar = %@", objectChar); // 打印出ASCII码值
       NSLog(@"还原后:%c", [objectChar charValue]);
 
       // 创建BOOL型对象
       NSNumber *objectBool = [NSNumber numberWithBool:basicBool];
       NSLog(@"objectBOOL = %@", objectBool);
       NSLog(@"还原后:%d", [objectBool boolValue]);
 
       //快速创建的方法
       NSNumber *intNum = @80; // ---> [NSNumber numberWithInt:80];
 
       NSNumber *floatNum = @3.14; // --->[NSNumber numberWithFloat:3.14];
 
       NSNumber *boolNum = @YES; // ---> [NSNumber numberWithBool:YES];
 
       NSNumber *charNum = @'a'; // ---> [NSNumber numberWithChar:'a'];
 
       // 快速创建变量需要将变量放在括号中
       double height = 1.83;
       NSNumber *doubleNum = @(height); // ---> [NSNumber numberWithDouble:height];
 
       NSArray *array = @[intNum, floatNum, boolNum, charNum, doubleNum];
       NSLog(@"array : %@", array);
 
       //判断两个对象的值是否相等
       if ([intNum isEqualToNumber:floatNum] == YES ) {
          NSLog(@"值相等");
       } else {
          NSLog(@"值不相等");
       }
 
       //比较两个对象的值大小
       NSNumber *myNumber = @30;
       if ([intNum compare:myNumber] == NSOrderedAscending) {
          NSLog(@"第一个数字小");
       } else { 
          NSLog(@"第一个数字大");
       }
}
NSNumber基本使用.png
- (nullable instancetype)initWithCoder:(NSCoder *)aDecoder NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithChar:(char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedChar:(unsigned char)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithShort:(short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedShort:(unsigned short)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInt:(int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInt:(unsigned int)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLong:(long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLong:(unsigned long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithLongLong:(long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedLongLong:(unsigned long long)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithFloat:(float)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithDouble:(double)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithBool:(BOOL)value NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithInteger:(NSInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER;
- (NSNumber *)initWithUnsignedInteger:(NSUInteger)value NS_AVAILABLE(10_5, 2_0) NS_DESIGNATED_INITIALIZER; ```
***
***

#2.int、 NSInteger、 NSUInteger、NSNumber之间的区别和联系
>  >int : 当使用int类型定义变量的时候,可以像写C程序一样去使用。当你不知道程序运行在哪种处理器架构时,你最好使用NSInteger,因为在有可能int在32位系统中只是int类型,而在64位系统,int可能变成long型。除非不得不使用int/long型,否则推荐使用NSInteger。

>NSInteger/NSUInteger是一种动态定义的类型,在不同的设备,不同的架构,有可能是int类型,有可能是long类型。NSUInteger是无符号的,即没有负数,NSInteger是有符号的。

>NSInteger是基础类型,NSNumber是一个类,如果需要存储一个数值,直接使用NSInteger是不行的,因为OC的集合当中存储的数据必须是OC对象。
上一篇 下一篇

猜你喜欢

热点阅读