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OC 第七天 字典 lesson7
NSDictionary 常用方法
NSDictionary用于保存具有映射关系的数据,因此,NSDictionary集合里保存着两组值:
一组用于保存NSDictionary里的key
另一组用于保存NSDictionary里的value
其中key与value都可以是任何引用类型的数据,key与value之间存在单向一对一的关系。(key不允许重复)
1.创建字典对象;
NSDictionary * dicYaoGe = [NSDictionary dictionaryWithObjectsAndKeys:@"瑶哥", @"name", @"?", @"sex", @"18", @"age", @"105", @"weight", nil]; NSLog(@"%@",dicYaoGe);
注意:此处写法比较反人类,value在前,key在后。
运行结果:2014-09-19 20:47:06.329 oc07_字典[6837:303] {
age = 18;
name = "\U7476\U54e5";
sex = "?";
weight = 105;
}
2.获取所有key值
NSLog(@"%@", [dicYaoGe allKeys]);运行结果:
2014-09-19 20:47:06.473 oc07_字典[6837:303] (
age,
sex,
weight,
name
)
3.获取所有value值
NSLog(@"%@", [dicYaoGe allValues]);运行结果:
2014-09-19 20:47:06.474 oc07_字典[6837:303] (
18,
"?",
105,
"\U7476\U54e5"
)
4.通过key值查询value
<span style="white-space:pre"> </span>NSLog(@"%@",[dicYaoGe objectForKey:@"weight"]);
运行结果:
2014-09-19 20:47:06.474 oc07_字典[6837:303] 105
快速遍历方法:for (NSString *key in dicYaoGe) { NSLog(@"%@ - %@",key ,[dicYaoGe objectForKey:key]); }
运行结果:
2014-09-19 20:47:06.475 oc07_字典[6837:303] age - 18
2014-09-19 20:47:06.476 oc07_字典[6837:303] sex - ?
2014-09-19 20:47:06.476 oc07_字典[6837:303] weight - 105
2014-09-19 20:47:06.477 oc07_字典[6837:303] name -瑶哥
NSMutableDictionary 常用方法
NSMutableDictionary *dicZijie = [NSMutableDictionary dictionaryWithObjectsAndKeys: @"王子杰",@"name", @"难以判断",@"sex", @"七老八十",@"age", @"200",@"weight",nil]; for (NSString *key in dicZijie) { NSLog(@"%@-%@",key , [dicZijie objectForKey:key]); }运行结果:
2014-09-19 20:57:55.310 oc07_字典[6858:303] age--七老八十
2014-09-19 20:57:55.311 oc07_字典[6858:303] hoby--男
2014-09-19 20:57:55.311 oc07_字典[6858:303] weight--200
2014-09-19 20:57:55.312 oc07_字典[6858:303] name--王子杰
1.添加键值对。
<span style="white-space:pre"> </span>[dicZijie setValue:@"LOL" forKey:@"hoby"];
2.修改key对应的value
<span style="white-space:pre"> </span>[dicZijie setValue:@"男" forKey:@"hoby"];
3.删除键值对。
<span style="white-space:pre"> </span>[dicZijie removeObjectForKey:@"sex"];
4.通过for循环遍历所有键值对
<span style="white-space:pre"> </span>for (NSString *key in dicZijie) { NSLog(@"%@-%@",key , [dicZijie objectForKey:key]); }运行结果:
2014-09-19 21:00:49.198 oc07_字典[6872:303] age-七老八十
2014-09-19 21:00:49.199 oc07_字典[6872:303] hoby-男
2014-09-19 21:00:49.199 oc07_字典[6872:303] weight-200
2014-09-19 21:00:49.200 oc07_字典[6872:303] name-王子杰
对于一个数组中字典的遍历:<span style="white-space:pre"> </span>NSDictionary *dicDaGe = [NSDictionary dictionaryWithObjectsAndKeys:@"大哥", @"name", @"卖药", @"hoby", @"男", @"sex",nil]; NSMutableArray *tongJi = [NSMutableArray arrayWithObjects:dicZijie,dicYaoGe,dicDaGe, nil]; for (NSDictionary *dic in tongJi) { NSLog(@"______________"); for (NSString *key in dic) { NSLog(@"%@--%@",key,[dic objectForKey:key]); } }运行结果:
2014-09-19 21:00:49.201 oc07_字典[6872:303] ______________
2014-09-19 21:00:49.201 oc07_字典[6872:303] age--七老八十
2014-09-19 21:00:49.201 oc07_字典[6872:303] hoby--男
2014-09-19 21:00:49.202 oc07_字典[6872:303] weight--200
2014-09-19 21:00:49.202 oc07_字典[6872:303] name--王子杰
2014-09-19 21:00:49.203 oc07_字典[6872:303] ______________
2014-09-19 21:00:49.203 oc07_字典[6872:303] age--18
2014-09-19 21:00:49.204 oc07_字典[6872:303] sex--?
2014-09-19 21:00:49.204 oc07_字典[6872:303] weight--105
2014-09-19 21:00:49.205 oc07_字典[6872:303] name--瑶哥
2014-09-19 21:00:49.205 oc07_字典[6872:303] ______________
2014-09-19 21:00:49.206 oc07_字典[6872:303] name--大哥
2014-09-19 21:00:49.206 oc07_字典[6872:303] hoby--卖药
2014-09-19 21:00:49.207 oc07_字典[6872:303] sex--男
OC 第七天 字典 lesson7