NSMutableDictionary--可變字典

NSMutableDictionary--可變字典

//
//  main.m
//  OC05-task-02
//
//  Created by Xin the Great on 15-1-25.
//  Copyright (c) 2015年 Xin the Great. All rights reserved.
//

#import 

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        ///////////////NSMutableDictionary--可變字典///////////////
        
        //初始化可變字典
        //空的字典
        NSMutableDictionary *dic1 = [NSMutableDictionary dictionary];
        NSLog(@"dic1 is %@", dic1);
        
        //給字典預期的一個空間
        NSMutableDictionary *dic2 = [NSMutableDictionary dictionaryWithCapacity:10];
        
        //添加元素
        [dic1 setObject:@"value1" forKey:@"key1"];
        [dic1 setObject:@"value2" forKey:@"key2"];
        [dic1 setObject:@"value3" forKey:@"key3"];
        
        //設置鍵值對，如果key已經存在，則是修改key所對應的value， 如果不存在，則創建一個新的鍵值對
        [dic1 setObject:@"value4" forKey:@"key4"];

        NSLog(@"dic1 is %@", dic1);
        
        
        //刪除元素
        //刪除指定的元素
        [dic1 removeObjectForKey:@"key2"];
        NSLog(@"dic1 is %@", dic1);

        //刪除所有的元素
        [dic1 removeAllObjects];
        NSLog(@"dic1 is %@", dic1);


        //字典的遍歷
        NSDictionary *dic = @{@"k1":@"v1",
                              @"k2":@"v2",
                              @"k3":@"v3",
                              @"k4":@"v4",
                              @"k5":@"v5",};
        
        //傳統遍歷

        NSArray *keys = [dic allKeys];
        
        for (int i = 0; i < dic.count; i++) {
            //獲取key
            NSString *key = keys[i];
            NSString *value = dic[key];
            NSLog(@"value[%@] is %@", key, value);
        }
        
        NSLog(@"------------------------------");
        
        //快速遍歷, 快速遍歷效率要高於傳統遍歷
        for (NSString *key in dic) {
            NSString *value = dic[key];
            NSLog(@"value[%@] is %@", key, value);
        }
        
        
        
        
    }
    return 0;
}