链式编程：是将多个操作（多行代码）通过点号(.)链接在一起成为一句代码,使代码可读性好。a(1).b(2).c(3)
特点：方法的返回值是block,block必须有返回值（本身对象），block参数（需要操作的值）
例：masonry
相关代码实现：
@class CalculterModel;
#import <Foundation/Foundation.h>
typedef CalculterModel *(^CalculateOption) (int);
@interface CalculterModel : NSObject
@property (nonatomic, assign) int result;
@property (nonatomic, copy) CalculateOption add;
@property (nonatomic, copy) CalculateOption sub;
@property (nonatomic, copy) CalculateOption muilt;
@property (nonatomic, copy) CalculateOption divide;
@end
#import "CalculterModel.h"
@implementation CalculterModel
//加
-(CalculateOption)add
{
return ^(int inputNum) {
self.result+=inputNum;
return self;
};
}
//减
-(CalculateOption)sub
{
return ^(int inputNum){
self.result-=inputNum;
return self;
};
}
//乘
-(CalculateOption)muilt
{
return ^(int inputNum){
self.result*=inputNum;
return self;
};
}
//除
-(CalculateOption)divide
{
return ^(int inputNum){
self.result/=inputNum;
return self;
};
}
实现的调用：
CalculterModel *model = [CalculterModel new];
int result = model.add(123).add(222).result;
NSLog(@"result = %d",result);
