7.8 編程思想

鏈?zhǔn)骄幊?/h2>

特點(diǎn)

• 是將多個(gè)操作（多行代碼）通過(guò)點(diǎn)號(hào)(.)鏈接在一起成為一句代碼,使代碼可讀性好仁卷。a(1).b(2).c(3)
• 方法的返回值是block，block必須有返回值（對(duì)象本身）管削，block參數(shù)（需要操作的值）
• 示例

@class Calculator;
typedef Calculator * (^addBlock)(int);
typedef Calculator * (^subBlock)(int);
typedef Calculator * (^mulBlock)(int);
typedef Calculator * (^diviBlock)(int);
@interface Calculator : NSObject

- (addBlock)add;
- (subBlock)sub;
- (mulBlock)mul;
- (diviBlock)divi;

@interface Calculator()
@property (assign , nonatomic)int currNum;
@end
@implementation Calculator
- (addBlock)add
{
    return ^(int a){
        self.currNum += a;
        NSLog(@"result=%d",self.currNum);
        return self;
    };
}
- (subBlock)sub{
    return ^(int a){
        self.currNum -= a;
        NSLog(@"result=%d",self.currNum);
       return self;
    };
}
- (mulBlock)mul{
    return ^(int a){
        self.currNum *= a;
        NSLog(@"result=%d",self.currNum);
        return self;
    };
}
- (diviBlock)divi{
    return ^(int a){
        self.currNum /= a;
        NSLog(@"result=%d",self.currNum);
       return self;
    };
}

  Calculator * ca = [[Calculator alloc] init];
    ca.add(10).sub(1).mul(9).divi(9);
@end

函數(shù)編程

特點(diǎn)

• 函數(shù)式編程思想：是把操作盡量寫(xiě)成一系列嵌套的函數(shù)或者方法調(diào)用杂彭。
  • 函數(shù)式編程特點(diǎn)：每個(gè)方法必須有返回值（本身對(duì)象）,把函數(shù)或者Block當(dāng)做參數(shù),block參數(shù)（需要操作的值）block返回值（操作結(jié)果）
  • 代表：ReactiveCocoa岩喷。
  • 用函數(shù)式編程實(shí)現(xiàn)视事，寫(xiě)一個(gè)加法計(jì)算器,并且加法計(jì)算器自帶判斷是否等于某個(gè)值.
  • 示例

    #import
    
    @class CaculatorMaker;
    
    @interface NSObject (CaculatorMaker)
    
    
    
    //計(jì)算
    
    + (int)makeCaculators:(void(^)(CaculatorMaker *make))caculatorMaker;
    
    @end
    
    #import "NSObject+CaculatorMaker.h"
    
    #import "CaculatorMaker.h"
    
    
    
    @implementation NSObject (CaculatorMaker)
    
    
    
    //計(jì)算
    
    + (int)makeCaculators:(void(^)(CaculatorMaker *make))block
    
    {
    
        CaculatorMaker *mgr = [[CaculatorMaker alloc] init];
    
        block(mgr);
    
        return mgr.iResult;
    
    }
    
    @end
    
    
    @interface CaculatorMaker : NSObject
    
    @property (nonatomic, assign) int iResult;
    
    //加法
    
    - (CaculatorMaker *(^)(int))add;
    
    
    
    //減法
    
    - (CaculatorMaker *(^)(int))sub;
    
    
    
    //乘法
    
    - (CaculatorMaker *(^)(int))muilt;
    
    
    
    //除法
    
    - (CaculatorMaker *(^)(int))divide;
    
    @end
    
      
    #import "CaculatorMaker.h"
    @implementation CaculatorMaker
    
    
    
    - (CaculatorMaker *(^)(int))add
    
    {
    
       return ^(int value)
    
        {
    
            _iResult += value;
    
            return self;
    
        };
    
    }
    
    @end
      
    //調(diào)用
      int iResult = [NSObject makeCaculators:^(CaculatorMaker *make) {
    
         make.add(1).add(2).add(3).divide(2);
    
       }];
    

響應(yīng)式編程

特點(diǎn)

• 響應(yīng)式編程思想：不需要考慮調(diào)用順序，只需要知道考慮結(jié)果礼旅，類(lèi)似于蝴蝶效應(yīng)膳叨，產(chǎn)生了一個(gè)事件，會(huì)影響很多東西痘系，這些事件就像流一樣傳播出去菲嘴，然后影響結(jié)果，借用面向?qū)ο蟮囊痪湓?huà)汰翠，萬(wàn)物皆是流龄坪，
• 代表：KVO