美文网首页iOS学习开发iOS DeveloperiOS开发
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)")

    }

    相关文章

      网友评论

        本文标题:简述swift中NSDictionary的几种用法

        本文链接:https://www.haomeiwen.com/subject/thgvjttx.html