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  • Objectc 总结之NSDictionary

    NSDictionary的常见用法总结

            NSArray *array1 = [NSArray arrayWithObjects:@"iphone",@"ipod",nil];

            NSArray *array2 = [NSArray arrayWithObjects:@"mac",@"imac",@"mac pro",nil];

            //类方法初始化自动释放

            NSDictionary *myDictionary = [NSDictionary dictionaryWithObjectsAndKeys:array1,@"mobile",array2,@"computers",nil];//注意用nil结束

            NSLog(@"myDictionary = %@",myDictionary);

            

            int dictSize = [myDictionary count];

            //访问字典中的值

            NSArray *mobile = [myDictionary objectForKey:@"mobile"];

            //从一个对象获取键

            NSArray *keys = [myDictionary allKeysForObject:array1];

            //获取字典中所有值得一个数组

            NSArray *values = [myDictionary allValues];

            //快速枚举

            for(id key in myDictionary)

            {

                NSLog(@"key: %@,value: %@",key,[myDictionary objectForKey:key]);

            }

            //如果字典只包含属性列表对象(NSData,NSDate,NSNumber,NSString,NSArrayNSDictionary)可以保存到文件中

            NSString *filePath = [[[NSBundlemainBundle]resourcePath]stringByAppendingPathComponent:@"dict.txt"];

            BOOL success = [myDictionary writeToFile:filePath atomically:YES];

            //用文件填充

            NSDictionary *myDict2 =[NSDictionary dictionaryWithContentsOfFile:filePath];

            

            //可变字典

            NSMutableDictionary *dictMutable = [[NSMutableDictionary alloc]initWithObjectsAndKeys:array1,@"mobile",array2,@"computer", nil];

            NSString *string4 = @"stringTV";

            //修改对象

            [dictMutable setObject:string4 forKey:@"media"];

            //删除对象

            [dictMutable removeObjectForKey:@"mobile"];

            //删除多个对象

            NSArray *keyArray =[NSArray arrayWithObjects:@"mobile",@"computer", nil];

            [dictMutable removeObjectForKey:keyArray];

            //删除所有对象

            [dictMutable removeAllObjects];

            

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  • 原文地址:https://www.cnblogs.com/superhappy/p/2332947.html
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