一、NSDictionary的創(chuàng)建

//字典的創(chuàng)建
    NSDictionary *dic1 = @{@"name":@"李四", @"age":@(24)};
    //這種創(chuàng)建字典的方式   前面的為value后面跟的是key
    NSDictionary *dic2 = [NSDictionary dictionaryWithObjectsAndKeys:@"李四", @"name", @(24), @"age", nil];
    NSDictionary *dic3 = [NSDictionary dictionaryWithDictionary:dic1];
    NSDictionary *dic4 = [[NSDictionary alloc] init];
    NSDictionary *dic5 = [[NSDictionary alloc] initWithObjectsAndKeys:@"李四", @"name", @(24), @"age", nil];
    NSDictionary *dic6 = [[NSDictionary alloc] initWithDictionary:dic1];
    NSLog(@"%@, %p", dic1, dic1);
    NSLog(@"%@, %p", dic2, dic2);
    NSLog(@"%@, %p", dic3, dic3);
    NSLog(@"%@, %p", dic4, dic4);
    NSLog(@"%@, %p", dic5, dic5);
    NSLog(@"%@, %p", dic6, dic6);
2018-06-28 14:03:47.056395+0800 NSDictionaryDemo[8144:477685] {
    age = 24;
    name = "\U674e\U56db";
}, 0x600000470640
2018-06-28 14:03:47.056587+0800 NSDictionaryDemo[8144:477685] {
    age = 24;
    name = "\U674e\U56db";
}, 0x600000470f40
2018-06-28 14:03:47.056775+0800 NSDictionaryDemo[8144:477685] {
    age = 24;
    name = "\U674e\U56db";
}, 0x600000470640
2018-06-28 14:03:47.057237+0800 NSDictionaryDemo[8144:477685] {
}, 0x60000000dd30
2018-06-28 14:03:47.057511+0800 NSDictionaryDemo[8144:477685] {
    age = 24;
    name = "\U674e\U56db";
}, 0x600000471200
2018-06-28 14:03:47.057997+0800 NSDictionaryDemo[8144:477685] {
    age = 24;
    name = "\U674e\U56db";
}, 0x600000470640

二艳狐、NSDictionary常用屬性

    NSDictionary *dic = @{@"name":@"李四", @"age":@(24)};
    //獲取字典中鍵值對個數(shù)
    NSLog(@"%ld", dic.count);
    //獲取字典中的所有key
    NSLog(@"%@", dic.allKeys);
    //獲取字典中的多有value
    NSLog(@"%@", dic.allValues);
2018-07-02 14:55:28.644107+0800 NSDictionaryDemo[4830:308743] 2
2018-07-02 14:55:28.644297+0800 NSDictionaryDemo[4830:308743] (
    name,
    age
)
2018-07-02 14:55:28.644470+0800 NSDictionaryDemo[4830:308743] (
    "\U674e\U56db",
    24
)

三给僵、NSDictionary常用方法

    NSDictionary *dic = @{@"name":@"李四", @"age":@(24)};
    //通過key值來獲取它多對應(yīng)的value
    NSLog(@"%@", [dic objectForKey:@"name"]);
    //遍歷字典中的數(shù)據(jù)
    [dic enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
        NSLog(@"key:%@ value:%@", key, obj);
    }];
    //根據(jù)value值排序凡人，得到key數(shù)組
    NSArray *keyArr = [dic keysSortedByValueUsingComparator:^NSComparisonResult(id  _Nonnull obj1, id  _Nonnull obj2) {
        NSString *str1 = [NSString stringWithFormat:@"%@", obj1];
        NSString *str2 = [NSString stringWithFormat:@"%@", obj2];
        return [str1 compare:str2];
    }];
    NSLog(@"%@", keyArr);
2018-07-02 15:06:13.766435+0800 NSDictionaryDemo[5039:322548] 李四
2018-07-02 15:06:13.766611+0800 NSDictionaryDemo[5039:322548] key:name value:李四
2018-07-02 15:06:13.766743+0800 NSDictionaryDemo[5039:322548] key:age value:24
2018-07-02 15:06:13.767102+0800 NSDictionaryDemo[5039:322548] (
    age,
    name
)

四滓玖、NSMutableDictionary的使用

    //NSMutableDictionary繼承于NSDictionary坪哄，所以上面說到的方法和屬性，NSMutableDictionary依然適用
    NSMutableDictionary *muDic1 = [NSMutableDictionary dictionary];
    //創(chuàng)建一個開辟空間大小為1的字典，如果超過他會自動擴大
    NSMutableDictionary *muDic2 = [NSMutableDictionary dictionaryWithCapacity:1];
    
    //向字典中添加數(shù)據(jù)
    [muDic1 setObject:@"李四" forKey:@"name"];
    NSLog(@"%@", muDic1);
    [muDic1 setValue:@(24) forKey:@"age"];
    NSLog(@"%@", muDic1);
    
    //根據(jù)key值刪除字典中的數(shù)據(jù)
    [muDic1 removeObjectForKey:@"age"];
    NSLog(@"%@", muDic1);
    //刪除字典中的所有數(shù)據(jù)
    [muDic1 removeAllObjects];
    NSLog(@"%@", muDic1);
    
    [muDic1 setObject:@"李四" forKey:@"name"];
    [muDic1 setValue:@(24) forKey:@"age"];
    [muDic1 setValue:@"boy" forKey:@"sex"];
    
    //根據(jù)key值數(shù)組刪除對應(yīng)的數(shù)據(jù)
    [muDic1 removeObjectsForKeys:@[@"age", @"name"]];
    NSLog(@"%@", muDic1);
    
    //向字典中添加數(shù)據(jù)的時候翩肌，如果key值已經(jīng)存在那么后來添加同樣key值數(shù)據(jù)饰剥，就會覆蓋以前的數(shù)據(jù)
    [muDic1 setObject:@"girl" forKey:@"sex"];
    NSLog(@"%@", muDic1);
    
    [muDic2 setObject:@"shanghai" forKey:@"address"];
    [muDic2 setObject:@"3000" forKey:@"income"];
    
    //把另一個字典中的所有數(shù)據(jù)添加到當前字典中。當出現(xiàn)相同key的時候摧阅，后面的值也會覆蓋原值
    [muDic1 addEntriesFromDictionary:muDic2];
    NSLog(@"%@", muDic1);
2018-07-02 15:28:58.889004+0800 NSDictionaryDemo[5375:350081] {
    name = "\U674e\U56db";
}
2018-07-02 15:28:58.889190+0800 NSDictionaryDemo[5375:350081] {
    age = 24;
    name = "\U674e\U56db";
}
2018-07-02 15:28:58.889317+0800 NSDictionaryDemo[5375:350081] {
    name = "\U674e\U56db";
}
2018-07-02 15:28:58.889429+0800 NSDictionaryDemo[5375:350081] {
}
2018-07-02 15:28:58.889676+0800 NSDictionaryDemo[5375:350081] {
    sex = boy;
}
2018-07-02 15:28:58.889766+0800 NSDictionaryDemo[5375:350081] {
    sex = girl;
}
2018-07-02 15:28:58.889875+0800 NSDictionaryDemo[5375:350081] {
    address = shanghai;
    income = 3000;
    sex = girl;
}