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简述swift中NSDictionary的几种用法

简述swift中NSDictionary的几种用法

作者: Jason_Wong | 来源:发表于2016-07-20 17:46 被阅读2471次

—————1.初始化( key一定要是可以hash的(String, Int, Float, Double, Bool), value没有要求)

vardict = ["name":"lnj","age":30]

print(dict)

vardict1:Dictionary= ["name":"lnj","age":30]

print(dict1)

vardict2:Dictionary = ["name":"lnj","age":30]

print(dict2)

vardict3:[String:AnyObject] = ["name":"lnj","age":30]

print(dict3)

vardict4:[String:AnyObject] =Dictionary(dictionaryLiteral: ("name","lnj"), ("age",30))

print(dict4)

—————2.数组类型

//不可变数组:

vardict5 = [:]

//可变数组:

letdict6  = [:]

—————3.获取

vardict7 = ["name":"lnj","age":30]

print(dict7["name"]!)

————4.修改

vardict8 = ["name":"lnj","age":30]

dict8["name"] ="iverson"

print(dict8["name"]!)

vardict9 = ["name":"lnj","age":30]

dict9.updateValue("iverson", forKey:"name")

print(dict9["name"]!)

—————5.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

vardict10 = ["name":"lnj","age":30]

ifletorignal =dict10.updateValue("iverson", forKey:"name")

{

print(dict10["name"]!)

print(orignal)

}

// 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

vardict11 = ["name":"lnj","age":30]

ifletorignal =dict11.updateValue("iverson", forKey:"abc")

{

print(dict11["abc"]!)

print(orignal)

}

print(dict11)

----------6.添加

vardict12 = ["name":"lnj","age":30]

dict12["height"] =175;

----------7.删除

vardict13 = ["name":"lnj","age":30]

dict13.removeValueForKey("name")

// 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

vardict14 = ["name":"lnj","age":30]

ifletorignal =dict14.removeValueForKey("names")

{

print(dict14)

print(orignal)

}

print(dict14)

vardict15 = ["name":"lnj","age":30]

dict15.removeAll(keepCapacity:true)

---------8.遍历字典

vardict16 = ["name":"lnj","age":30]

for(key , value)indict16

{

print("key =\(key) value =\(value)")

}

vardict17 = ["name":"lnj","age":30]

forkeyindict17.keys

{

print("key =\(key)")

}

vardict18 = ["name":"lnj","age":30]

forvalueindict18.values

{

print("value =\(value)")

}

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