kotlin 解构函数声明和运算符重载operator

kt的解构函数声明和运算符重载operator学习笔记###

/**
 * DESC   : kt的解构函数声明和运算符重载operator
 */
const val KtBaseObjectTest07_TAG = "KtBaseObjectTest07"

class TeacherBean(var name: String, var age : Int, var info : String) {

    /**
     * 注意：component的顺序必须和参数一一对应，从component1开始到2，3.......
     * 函数声明为operator类型
     */
    operator fun component1() = name
    operator fun component2() = age
    operator fun component3() = info
}

data class TeacherBean2(var name: String, var age : Int, var info : String)


/**
 * 为了方便测试，使用data class, 使用toString方法打印
 * 测试运算符重载
 */
data class ProductInfo(val price1: Int, val price2: Int) {
    operator fun plus(otherProductInfo: ProductInfo) : ProductInfo {
        return ProductInfo(price1 + otherProductInfo.price1, price2 + otherProductInfo.price2)
    }
}


class KtBaseObjectTest07 {

    fun testComponent01() {

        //testComponent01==>com.xyaty.kotlinbasedemo.base05.TeacherBean@9381bfb
        Log.d(KtBaseObjectTest07_TAG, "testComponent01==>"+TeacherBean("张三", 30, "english"))

        //testComponent01==>TeacherBean2(name=李四, age=31, info=china)
        Log.d(KtBaseObjectTest07_TAG, "testComponent01==>"+TeacherBean2("李四", 31, "china"))

        /**
         * 如果不加operator，使用下面的解构代码会出错
         * operator fun component1() = name
         */
        val(name, age, info) = TeacherBean("laowang", 50, "游民")
        //testComponent01==>解构...name=laowang, age=50, info=游民
        Log.d(KtBaseObjectTest07_TAG, "testComponent01==>解构...name="+name
            +", age="+age+", info="+info)

        val(name2, age2, _) = TeacherBean2("laowang", 50, "老王信息不接收")
        //testComponent01==>解构...name2=laowang, age2=50
        Log.d(KtBaseObjectTest07_TAG, "testComponent01==>解构...name2="+name2
                +", age2="+age2)
    }

    /**
     * 运算符重载
     */
    fun testOperator01() {
        val p1  = ProductInfo(20, 200)
        val p2 = ProductInfo(30, 300)

        val p3 = p1.plus(p2)
        //testOperator01==>ProductInfo(price1=50, price2=500)
        Log.d(KtBaseObjectTest07_TAG, "testOperator01==>"+p3)

    }
}