swift中数组和字典的创建，使用，遍历

这里是数组的使用

• 创建一个指定类型以及指定默认值和数组大小的数组，一个是字面量的，一个是NSArray的

var someInts = [Int](repeating: 0, count: 3)//创建一个指定类型以及指定默认值和数组大小的数组
//print(someInts)//0 0 0
someInts[0] = 1;
//print(someInts)//1 0 0
someInts.append(2);
//print(someInts)//1 0 0 2
//print(someInts+[3])//1 0 0 2 3

someInts.insert(10, at: 0)
//print(someInts)//10, 1, 0, 0, 2

someInts.remove(at: 0)
//print(someInts)//1, 0, 0, 2
//someInts.removeLast()删除第一个
//someInts.removeLast()//删除最后一个

someInts.removeAll()//删除全部
print(someInts)//

        var arr1: NSArray = ["1","2","3","4","5"];//创建一个数据
        print(arr1[0]);//1 输出打印某一个值
        print(arr1.object(at: 0));//1 和上面是等价的
        
        var arr2: NSArray = NSArray.init(array: arr1)
        print(arr2);//1 2 3 4 5
        
        var arr3: NSArray = NSArray.init(object: "2");
        print("arr3:(arr3)")//2

        var arr4: NSArray = NSArray.init(objects: "2","3");
        print("arr4:(arr4)")// 2 3

• 可变数组的使用

        var arr1: NSArray = ["1","2","3","4","5"];
        var arr2: NSMutableArray = NSMutableArray.init();
        arr2.addObjects(from: arr1 as! [Any]);//把arr1中所有的obj添加到arr2
        print(arr2);//1 2 3 4 5
        arr2.add("6")//添加一个对象
        print(arr2);//1 2 3 4 5 6
        arr2.insert("0", at: 0);//在指定的地方插入一个对象
        print(arr2);//0 1 2 3 4 5 6
        arr2.remove("0");//删除指定的对象
        print(arr2);//1 2 3 4 5 6
        arr2.removeLastObject();//删除最后一个对象
        print(arr2);//1 2 3 4 5
        arr2.removeObject(at: 1);//删除指定索引的对象
        print(arr2);//1 3 4 5
        arr2.replaceObject(at: 2, with: "10")//覆盖指定索引的对象
        print(arr2);//1 3 10 5
        arr2.removeAllObjects();//清空数组

• 数组的遍历的两种方式

        for obj in arr1 {//数据遍历
            print(obj);// 1 2 3 4 5
        }

        for (index,item) in arr1.enumerated()
        {
            print("index:(index) obj:(item)",terminator: "    ");
            //输出结果 index:0 obj:1    index:1 obj:2    index:2 obj:3    index:3 obj:4    index:4 obj:5   
        }

字典的使用

• 创建一个指定key类型和value类型的字典

        //var someDict =  [KeyType: ValueType]()//创建一个指定key类型和value类型的字典
        var dic1 = [String:String]();
        dic1["1"] = "one"
        dic1["2"] = "Two"
        dic1["3"] = "Three"
//        print(dic1);//["2": "Two", "1": "one", "3": "Three"]
//        print(dic1["1"]);//Optional("one")  访问指定key的值
        
        var dic2:[Int:String] = [1:"One", 2:"Two", 3:"Three"]
        print(dic2);//[3: "Three", 1: "One", 2: "Two"]
        dic2.updateValue("first", forKey: 1);//修改指定key的值
        print(dic2);//[3: "Three", 1: "first", 2: "Two"]
        dic2.removeValue(forKey: 1);//移除指定key的值
        print(dic2);//[3: "Three", 2: "Two"]

• NSDictionary的使用

       var dic1: NSDictionary = NSDictionary.init(objects: ["1","2","3"], forKeys: ["one" as  NSCopying,"two" as NSCopying,"three" as NSCopying]);
        print(dic1);
        {
            one = 1;
            three = 3;
            two = 2;
        }
        print(dic1.object(forKey: "one"))//Optional(1)
        print(dic1.allKeys);//[one, two, three]

• NSMutableDictionary的使用

       var dic1: NSDictionary = NSDictionary.init(objects: ["1","2","3"], forKeys: ["one" as NSCopying,"two" as NSCopying,"three" as NSCopying]);
        var dic2: NSMutableDictionary = NSMutableDictionary.init(dictionary: dic1);
        print(dic2);
        dic2.setObject("4", forKey: "four" as NSCopying);//新增
        print(dic2);
        dic2.removeObject(forKey: "four");//删除
        print(dic2)
        dic2.setObject("11", forKey: "one" as NSCopying)//修改
        print(dic2);
        dic2["one"] = "12"//修改
        print(dic2);
        dic2.removeAllObjects();//删除全部
        print(dic2);

• 字典的遍历

        for (key, value) in dic2 {
            print("字典 key (key) -  字典 value (value)")
        }

        for (key, value) in dic2.enumerated() {
            print("字典 key (key) -  字典 (key, value) 对 (value)")
        }

•  print的基础使用

for x in 0...10{
    print("(x) ", terminator: "*")//terminator是指链接符号
}
print()
print(1.0, 2.0, 3.0, 4.0, 5.0, separator: "*")//separator设置连接符号