[移动开发]Kotlin学习体会-简单的数据类型和类创建

找了个学习大纲，从语法先开始吧，先了解下数据类型

大致有以下几种类型

Int, Short, Long, Float, Double, Byte, Char

相比java,首字母都大写了，其他区别不大

变量和类在使用过程中，省略了很多代码，感觉很舒服，测试demo如下，先写一部分，后面再添加

/**
 * SDD:ADD FILE BY SHUCHNELIN ON 21/10/20
 */
class KotlinDataStructureTest : Activity(){
    val TAG = "KotlinDataStructureTest"
    //java里是boolean
    var boolFlag:Boolean = true
    //java int
    var intFlag:Int = 1
    //java short
    var shortFlag:Short = 1
    //jave long
    var longFlag:Long = 1L
    //java float
    var floatFlag:Float = 1.0F
    //java double
    var doubleFlag:Double = 1.10
    //java byte
    var byteFlag:Byte = 1
    //java char
    var charFlag:Char = 'a'
    //小写的char无法识别
    //var litteCharFlag:char='a'

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        test()
    }

    fun test() {
        //不会报错，可以相加,addDoubleAndInt输出2.1
        val addDoubleAndInt = doubleFlag + intFlag
        //会报错，提示不可与double相加
        //val addDoubleAndInt2:Int = doubleFlag + intFlag
        //java是通过+号连接变量，kotlin直接使用$
        Log.d(TAG, "test addDoubleAndInt: $addDoubleAndInt")
    }

    //可定义一个无参空类
    class Girl
    //定义带两个参数的类
    class Girl2(var character:String, var face:String, var sound:String)
    class Girl3(var character:String, var face:String, var sound:String) {
        init {
            Log.d("KotlinDataStructureTest", "she is mine")
        }
    }
    //这种有两个构造方法的类的写法不正确
    // class Girl4 constructor(var character: String) constructor(var face: String, var sound: String)
    //定义三个构造方法的类
    class Girl4 constructor(var character: String) {
        constructor(var face: String, var sound: String)
        constructor(var sound: String, var height:String, var breast:String)
    }
    val myGirl:Girl = Girl()
    //:Girl2可省略，Kotlin可自动获取后面的初始化参数类型
    val myGirl2:Girl2 = Girl2("softy", "beauty", "sweet")
    //初始化时即会自动运行init方法
    val myGirl3 = Girl3("softy", "beauty", "sweet")
    //分别用三个构造方法创建对象
    val myGirl41 = Girl4("softy")
    val myGirl42 = Girl4("beauty", "sweet")
    val myGirl43 = Girl4("sweet", "165", "E")

}