Swift5 字典（Dictionary）操作

Swift字典创建

let dic : Dictionary = [:]
let dic1 : [String : Any] = [:]
let dic2 = ["name": "Alice", "age": 10] as [String : Any]
print(dic, dic1, dic2)
// 结果：[:] [:] ["age": 10, "name": "Alice"]

Swift字典判空

let dic : Dictionary = [:]
print(dic.isEmpty)
//结果：true

Swift字典键值对个数

let dic : Dictionary = ["name":"Alice", "age": 22]
print(dic.count)
// 结果：2

Swift字典所有键值对

let dic : Dictionary = ["name":"Alice", "age": 22]
print(dic.keys, dic.values)
// 结果：["age", "name"] [22, "Alice"]

Swift字典取值

let dic : Dictionary = ["name":"Alice", "age": 22]
 print(dic["age"]!,dic["notExist"])
 // 结果：22 nil

Swift字典元素增删改

var dic : Dictionary = ["name":"Alice", "age": 22]
dic.updateValue(21, forKey: "age")
print(dic)
// 结果： ["age": 21, "name": "Alice"]

dic["gender"] = "male"
print(dic)
// 结果：["name": "Alice", "age": 21, "gender": "male"]

dic.removeValue(forKey: "name")
 print(dic)
// 结果：["gender": "male", "age": 21]
        

Swift字典遍历

let dic : Dictionary = ["name":"Alice", "age": 22]
for obj in dic {
    print(obj.key, obj.value)
}
// 结果：name Alice age 22

Swift5 字符串（String）操作
Swift5 字符（Character）操作
Swift5 数组（Array）操作
Swift5 字典（Dictionary）操作
Swift5 集合（Set）操作
Swift5 简单使用
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