标签：字典 nsdictionary 无序字典排序 遍历
一:字典的基础讲解
NSDictionary（字典），NSDictionary类似于 .net中的parameter,l类似于java中的map。
通过唯一的key找到对应的值，一个key只能对应一个只，而多个key可以对应同一个值。NSDictionary 在初始化之后，就不可以再进行修改。
| 使用类方法创建NSDictionary对象。 |
初始化一个NSDictionary对象。使用+ (id)dictionaryWithObject:(id)object forKey:(id)key;
NSDictionary* dic = [NSDictionary dictionaryWithObject:@"values1" forKey:@"key1"];
NSLog(@"%@",dic);
//结果
2014-08-26 19:13:29.274 Nsdictonary[288:707] {
key1 = values1;
}
初始化一个NSDictionary对象。使用+ (id)dictionaryWithObjectsAndKeys:(id)firstObject, ... NS_REQUIRES_NIL_TERMINATION;
NSDictionary* dic = [NSDictionary dictionaryWithObjectsAndKeys:
@"values1",@"key1"
@"values2",@"key2"
@"values3",@"key3" ,nil];
NSLog(@"%@",dic);、
//结果
初始化一个NSDictionary对象。使用+ (id)dictionaryWithObjects:(NSArray *)objects forKeys:(NSArray *)keys;
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSLog(@"%@",dic);
结果：
2014-08-26 19:30:34.286 Nsdictonary[345:707] {
key1 = values1;
key2 = values2;
key3 = values3;
}
| 使用实例方法创建NSDictionary |
创建一个空的字典：
NSDictionary* dic = [[NSDictionary alloc]init];
NSLog(@"%@",dic);
通过两个数组创建字典对象。
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic = [[NSDictionary alloc] initWithObjects:values forKeys:keys];
NSLog(@"%@",dic);
通过一个字典来创建一个新的字典。
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSLog(@"%@",dic);
计算一个字典中有多少个键值对：??????
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSLog(@"count :%lu",[dic count]);
NSLog(@"%@",dic1);
结果：
2014-08-26 19:44:54.809 Nsdictonary[439:707] count :3
2014-08-26 19:44:54.817 Nsdictonary[439:707] {
key1 = values1;
key2 = values2;
key3 = values3;
}
通过健来去对应的值：
NSObject* obj = [dic objectForKey:@"key1"];
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSObject* obj = [dic objectForKey:@"key1"];
NSLog(@"key1 = %@",obj);
结果：
2013-08-26 19:47:24.175 Nsdictonary[453:707] key1 = values1
将字典写入文件中：
[dic writeToFile:path atomically:YES];
|
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSString* path =@"/Users/administrator/Desktop/test.xml";
NSLog(@"dic:%@",dic);
[dic writeToFile:path atomically:YES];
NSDictionary* dicTest = [NSDictionary dictionaryWithContentsOfFile:path];
NSLog(@"dicTest: %@",dicTest);
结果：
2014-08-26 19:55:31.276 Nsdictonary[500:707] dic:{
key1 = values1;
key2 = values2;
key3 = values3;
}
2014-08-26 19:55:31.294 Nsdictonary[500:707] dicTest: {
key1 = values1;
key2 = values2;
key3 = values3;
}
返回所有的keys：
NSArray* retKeys = [dic allKeys];：
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSArray* retKeys = [dic allKeys];
NSLog(@"all keys :%@",retKeys);
结果：
2013-08-26 19:58:48.871 Nsdictonary[515:707] all keys :(
key1,
key3,
key2
)
返回所有的值：allvalues
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSDictionary* dic2 = [NSDictionary dictionaryWithObjects:values forKeys:keys];
NSDictionary* dic = [[NSDictionary alloc] initWithDictionary:dic2];
NSArray* retValues = [dic allValues];
NSLog(@"all keys :%@",retValues);
结果：
2014-08-26 19:59:57.768 Nsdictonary[532:707] all keys :(
values1,
values3,
values2
)
|
NSMutableDictionary 创建插入删除 |
|
创建一个
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
结果：
2014-08-26 20:11:56.388 Nsdictonary[634:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
插入一个新的健值对：
[dic setObject:@"values4" forKey:@"key4"];
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
[dic setObject:@"values4" forKey:@"key4"];
NSLog(@"dic : %@",dic);
结果：
2014-08-26 20:15:36.330 Nsdictonary[680:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2013-08-26 20:15:36.338 Nsdictonary[680:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
key4 = values4;
}
移除一个健值对：
[dic removeObjectForKey:@"key1"];
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
[dic removeObjectForKey:@"key1"];
NSLog(@"dic : %@",dic);
结果：
2014-08-26 20:17:33.980 Nsdictonary[695:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2013-08-26 20:17:34.013 Nsdictonary[695:707] dic : {
key2 = values2;
key3 = values3;
}
移除所有健值对：
removeAllObjects
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
[dic removeAllObjects];
NSLog(@"dic : %@",dic);
结果：
2013-08-26 20:18:38.027 Nsdictonary[711:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2013-08-26 20:18:38.036 Nsdictonary[711:707] dic : {
}
遍历字典：
for(id objects in dic)
|
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
//类似于foreach
for(id objects in dic)
{
NSObject* obj = [dic objectForKey:objects];
NSLog(@"%@ = %@",objects,obj);
}
结果：
2014-08-26 20:24:00.303 Nsdictonary[757:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2014-08-26 20:24:00.353 Nsdictonary[757:707] key1 = values1
2014-08-26 20:24:00.362 Nsdictonary[757:707] key3 = values3
2014-08-26 20:24:00.371 Nsdictonary[757:707] key2 = values2
迭代器遍历字典：
NSEnumerator* em = [dic keyEnumerator];
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
NSEnumerator* em = [dic keyEnumerator];
id key =nil;
while(key = [em nextObject])
{
NSObject* obj = [dic objectForKey:key];
NSLog(@"%@ = %@",key,obj);
}
结果：
2014-08-26 20:28:23.753 Nsdictonary[771:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2014-08-26 20:28:23.871 Nsdictonary[771:707] key1 = values1
2014-08-26 20:28:23.873 Nsdictonary[771:707] key3 = values3
2014-08-26 20:28:23.879 Nsdictonary[771:707] key2 = values2
block遍历字典：
[dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
NSLog(@"%@ = %@",key,obj);
}];
NSArray* values = [NSArray arrayWithObjects:@"values1",@"values2",@"values3", nil];
NSArray* keys = [NSArray arrayWithObjects:@"key1",@"key2",@"key3", nil];
NSMutableDictionary* dic2 = [NSMutableDictionary dictionaryWithObjects:values forKeys:keys];
NSMutableDictionary* dic = [[NSMutableDictionary alloc] initWithDictionary:dic2];
NSLog(@"dic : %@",dic);
[dic enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
NSLog(@"%@ = %@",key,obj);
}];
结果：
2014-08-26 20:32:09.894 Nsdictonary[789:707] dic : {
key1 = values1;
key2 = values2;
key3 = values3;
}
2014-08-26 20:32:09.906 Nsdictonary[789:707] key1 = values1
2014-08-26 20:32:09.917 Nsdictonary[789:707] key2 = values2
2014-08-26 20:32:09.913 Nsdictonary[789:707] key3 = values3
IOS中 NSDictionary无序字典排序
按NSDictionary的key来对其进行排序：
先将dict的allkeys赋给一个数组，然后通过sortedArrayUsingComparator:方法对数组排序，然后遍历数组取字典对应key的值就ok
NSArray *keys = [dict allKeys];
NSArray *sortedArray = [keys sortedArrayUsingComparator:^NSComparisonResult(idobj1, id obj2) {
return [obj1 compare:obj2 options:NSNumericSearch];
}];
for (NSString *categoryId in sortedArray) {
??
NSLog(@"[dict objectForKey:categoryId] === %@",[dictobjectForKey:categoryId]);
}
方法二：
NSString *filePath = [[NSBundle mainBundle]pathForResource:@"students" ofType:@"plist"];
NSDictionary *stuDic = [NSDictionary dictionaryWithContentsOfFile:filePath];
self.studentIndexArray = [NSMutableArray arrayWithCapacity:1];
NSArray *arr = [[stuDic allKeys] sortedArrayUsingSelector:@selector(compare:)];
ios objective-c之－9:字典，可变字典 （NSDictonary NSMutableDictoray）
标签：字典 nsdictionary 无序字典排序 遍历
原文地址：http://blog.csdn.net/sammyieveo/article/details/41867213
