先来一个demo

data class Point(val x:Int,val y:Int) {
operator fun plus(other:Point):Point{
    return Point(x+other.x,y+other.y)
}
}

fun main(args: Array<String>) {
val p1=Point(1,6)
val p2=Point(7,334)
println(p1+p2)
}

结果：Point(x=8, y=340)

重载运算符：

a*b   函数名：times
a/b   函数名：div
a%b 函数名：mod
a+b  函数名：plus
a-b  函数名：minus

特殊运算符

shl——带符号左移
shr——带符号右移
ushr——无符号右移
and——按位与
or——按位或
xor——按位异或
inv——按位取反

一元运算符

+a unaryPlus
+b unaryMinus
!a not
++a,a++ inc
--a,a--    dec

forEach一种写法：

(0..n).forEach{ println(it)}
直接：
val n=9
println(0..(n+1))
结果不会遍历，而是：0..10

解构函数：

 val (x,y)=p1;
 println(x)

data class Test1(val name:String,val extension:String)

fun splitFileName(fullName:String):Test1{
val result=fullName.split('.',limit = 2)
return Test1(result[0],result[1])
}

fun main(args: Array<String>) {
val (name,external )= splitFileName("ddfeweweww.ttyuiii")
println(name)
}

接口监听：

class Person  (val name :String,age : Int ,salary :Int): PropertyChangeAware() {

var age:Int =age
    set(newValue){
        val oldValue=field
        field=newValue
        changeSupport.firePropertyChange("age",oldValue,newValue)
    }

var salary:Int =salary
    set(newValue){
        val oldValue=field
        field=newValue
        changeSupport.firePropertyChange("salary",oldValue,newValue)
    }

}

open class PropertyChangeAware{
  protected val changeSupport=PropertyChangeSupport(this)

fun addPropertyyChangeListener(listener:PropertyChangeListener){
    changeSupport.addPropertyChangeListener(listener)
}

fun removePropertyChangeListenerListener(listener: PropertyChangeListener){
    changeSupport.removePropertyChangeListener(listener)
}
}

 val p=Person("dsdsf",23,500)
p.addPropertyyChangeListener(
        PropertyChangeListener {
            evt ->  println("Property ${evt.propertyName} changed from ${evt.oldValue} to ${evt.newValue}"  )
        }
)

p.age=35