swift基础语法(10-字典)

定义字典

OC:

NSDictionary *dict =[NSDictionary dictionaryWithObject:

                                  @“qbs" forKey:@"name"];

NSLog(@"%@", dict);

输出结果:

2016-01-06 15:09:11.214 OCTest[3773:761032] {
    name = gxq;

}

NSDictionary *dict =[NSDictionary dictionaryWithObjectsAndKeys:

                                  @"name", @"qbs",

                                  @"age", @20, nil];

NSLog(@"%@", dict);

输出结果:

2016-01-06 15:13:39.853 OCTest[3831:792730] {
    gxq = name;
    20 = age;

}

NSDictionary *dict = @{@"name":@"qbs", @"age":@20};

NSLog(@"%@", dict);

输出结果:

2016-01-06 15:14:57.616 OCTest[3841:801710] {
    age = 20;
    name = gxq;

}

swift:

key一定要是可以hash的(String, Int, Float, Double, Bool)

value没有要求

var dict = ["name":"qbs", "age":20]

print(dict)

var dict1:Dictionary = ["name":"qbs", "age":20]

print(dict1)

var dict2:Dictionary<String,AnyObject> = ["name":"qbs", "age":20]

print(dict2)

var dict3:[String:AnyObject] = ["name":"qbs", "age":20]

print(dict3)

var dict4:[String:AnyObject] =

Dictionary(dictionaryLiteral: ("name", "qbs"), ("age", 20))

print(dict4)

输出结果:

["age": 20, "name": qbs]

["age": 20, "name": qbs]

["age": 20, "name": qbs]

["age": 20, "name": qbs]

["age": 20, "name": qbs]

 

可变字典:

var dict5 = [:]

不可变字典:

let dict6  = [:]

 

字典操作

OC:

获取

NSDictionary *dict = @{@"name":@"qbs", @"age":@20};

NSLog(@"%@", dict[@"name"]);

输出结果:

2016-01-06 15:26:00.351 OCTest[3923:881138] gxq

 

修改

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @"name", @"qbs",

                     @"age", @20, nil];

dict[@"name"] = @"iversion";

NSLog(@"%@", dict[@"name"]);

 

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                    @"name", @"qbs",

                    @"age", @20, nil];

[dict setObject:@"iversion" forKey:@"name"];

NSLog(@"%@", dict[@"name"]);

 

输出结果:

2016-04-01 15:27:01.704 OCTest[3933:890317] iversion

2016-04-01 15:28:21.398 OCTest[3943:899613] iversion

 

swift:

获取

var dict = ["name":"qbs", "age":20]

print(dict["name"]!)

输出结果: gxq

 

 

修改

var dict = ["name":"qbs", "age":20]

dict["name"] = "iverson"
print(dict["name"]!)

var dict1 = ["name":"qbs", "age":20]

dict1.updateValue("iverson", forKey: "name")

print(dict["name"]!)

输出结果:

iverson

iverson

 

更新

updateValue返回一个可选类型

如果字典中不存在需要更新的key, 那么返回nil, 如果存在返回原始值

var dict = ["name":"qbs", "age":25]

if let orignal = dict.updateValue("iverson", forKey: "name")
{
    print(dict["name"]!)
    print(orignal)

}

输出结果:

iverson

qbs

 

updateValue返回一个可选类型

如果字典中不存在需要更新的key, 那么返回nil并且会将新的键值对添加到字典中

var dict = ["name":"qbs", "age":25]

if let orignal = dict.updateValue("iverson", forKey: "abc")
{
    print(dict["abc"]!)
    print(orignal)
}

print(dict)

输出结果: ["abc": iverson, "age": 25, "name": qbs]

添加

OC:

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                   @"name", @"qbs",

                   @"age", @25, nil];

dict[@"height"] = @100;

NSLog(@"%@", dict);

输出结果:

2016-04-01 15:35:11.734 OCTest[4025:946250] {

    qbs = name;

    25 = age;
    height = 100;

}

 

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                    @"name", @“QBS",

                     @"age", @30, nil];

[dict setObject:@200 forKey:@"height"];

NSLog(@"%@", dict);

输出结果:

2016-04-01 15:36:15.768 OCTest[4035:953931] {

    QBS = name;

    30 = age;
    height = 200;

}

 

swift:

var dict = ["name”:"Qbs", "age":50]

dict["height"] = 160;

print(dict)

输出结果: ["height": 160, "age": 50, "name": Qbs]

 

 

删除

OC:

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @"qbs",@"name",

                     @30,@"age",nil];

[dict removeObjectForKey:@"name"];

NSLog(@"%@", dict);

输出结果:

2016-04-01 15:40:37.801 OCTest[4058:981747] {

    age = 30;

}

 

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @“qbs",@"name",

                     @30,@"age",nil];

[dict removeAllObjects];

NSLog(@"%@", dict);

输出结果:

2016-04-01 15:41:20.705 OCTest[4068:989096] {

}

swift:

 

var dict = ["name":"qbs", "age":10]

dict.removeValueForKey("name")

print(dict)

输出结果: ["age": 10]

 

removeValueForKey返回一个可选类型

如果字典中不存在需要删除的key, 那么返回nil并且不会执行任何操作

如果存在则删除key对应的值, 并且返回被删除的值

var dict = ["name”:"abs", "age”:20]

if let orignal = dict.removeValueForKey("names")
{
    print(dict)
    print(orignal)
}

print(dict)

输出结果:["age": 30, "name": qbs]

 

var dict = ["name”:”qbs", "age":30]

dict.removeAll(keepCapacity: true)

 

遍历字典

OC:

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @"qbs",@"name",

                     @40,@"age",nil];[dictenumerateKeysAndObjectsUsingBlock:^(idkey,idobj,BOOL*stop) {

      NSLog(@"key = %@ value = %@", key, obj);

}];

输出结果:

2016-04-01 15:45:59.810 OCTest[4117:1022823] key = name value = qbs

2016-04-01 15:45:59.811 OCTest[4117:1022823] key = age value = 40

 

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @“qbs", @"name",

                     @40, @"age", nil];

NSArray *keys = [dict allKeys];

for (NSString *key in keys) {

    NSLog(@"%@", key);

}

输出结果:

2016-04-01 15:48:07.861 OCTest[4137:1039198] name

2016-04-01 15:48:07.862 OCTest[4137:1039198] age

NSMutableDictionary *dict =

[NSMutableDictionary dictionaryWithObjectsAndKeys:

                     @"qbs", @"name",

                     @40, @"age", nil];

NSArray *keys = [dict allValues];

for (NSString *key in keys) {

    NSLog(@"%@", key);

}

输出结果:

2016-04-01 15:49:20.375 OCTest[4148:1049548] gxq

2016-04-01 15:49:20.376 OCTest[4148:1049548] 40

 

 

var dict1 = ["name”:"Qbs", "age":30]

for (key , value) in dict1
{
    print("key = (key) value = (value)")

}

输出结果:

key = age value = 30

key = name value = Qbs

 

 

var dict2 = ["name”:"Qbs", "age":40]

for key in dict2.keys
{
    print("key = (key)")

}

输出结果:

key = age

key = name

 

var dict3 = ["name”:"Qbs", "age":50]

for value in dict3.values
{
    print("value = (value)")

}

输出结果:

value = 50

value = Qbs