一元操作符
| 表达式 | 对应的函数 |
| +a | a.unaryPlus() |
| -a | a.unaryMinus() |
| !a | a.not() |
| a++ | a.inc() |
| a-- | a.dec() |
fun main(arg: Array<String>) {
var a = "a"
println(a++)
println(a)
println(++a)
}
operator fun String.inc():String{//重载String的++
return this +this
}
二元操作符
| 表达式 | 对应的函数 |
| a+b | a.plus(b) |
| a-b | a.minus(b) |
| a*b | a.tims(b) |
| a/b | a.div(b) |
| a%b | a.mod(b) |
| a.b | a.rangeTo(b) |
| a in b | b.contains(a) |
| a !in b | !b.contains(a) |
fun main(arg: Array<String>) {
var s= "hello"
print(s*10)
}
//重载乘法操作符
operator fun String.times(other:Any?):String{
var result = ""
if (other!= null){
if (other is Int)
for (i in 1..other){
result+=this
}
}
return result
}
方括号操作符重载
| 表达式 | 对应的函数 |
| a[i] | a.get(i) |
| a[i,j] | a.get(i,j) |
| a[i_1,...,i_n] | a.get(i_1,..,i_n) |
| a[i]=b | a.set[i,b] |
| a[i,j]=b | a.set(i,j,b) |
| a..b | a.rangeTo(b) |
| a[i_1,...,i_n]=b | a.set(i_1,..i_n,b) |
fun main(arg: Array<String>) {
val arr1 :Array<Any> = arrayOf("3", "2")
val arr2 :Array<Any> = arrayOf("9", "8")
println("arr1[1] = ${arr1[1]}")
println("arr2[1] = ${arr2[1]}")
val arr3 = arrayOf(arr1, arr2)
println("arr3[0][0] = ${arr3[0][0]}")
}
//重载一维数组[i]操作符
operator fun Array<Any>.get(i:Int):Int{
if (this[i] is Int){
return this[i] as Int
}else if (this[i] is String){
try {
return this[i].toString().toInt()
}catch (e:Exception){
}
}
return 0
}
//重载二维数组[i][j]操作符
operator fun Array<Array<Any>>.get(i:Int,j:Int):Int{
if (this[i][j] is Int){
return this[i][j] as Int
}else if (this[i][j] is String){
try {
return this[i][j].toString().toInt()
}catch (e:Exception){
}
}
return 0
}
赋值操作符重载
| 表达式 | 对应的函数 |
| a+=b | a.pulsAssign(b) |
| a-=b | a.minusAssign(b) |
| a*=b | a.timesAssign(b) |
| a/=b | a.divAssign(b) |
| a%=b | a.modAssign(b) |
fun main(arg: Array<String>) {
val myString = myString()
myString.value="sss"
myString*=3
print(myString)
}
class myString{
var value :String = "hello"
override fun toString(): String {
return "myString(value='$value')"
}
}
operator fun myString.timesAssign(n:Int):Unit{
val v =this.value
for (i in 1..n-1)
this.value+=v
}
逻辑操作符重载
| 表达式 | 对应的函数 |
| a>b | a.compaerTo(b)>0 |
| a<b | a.compaerTo(b)<0 |
| a>=b | a.compaerTo(b)>=0 |
| a<=b | a.compaerTo(b)<=0 |
| a==b | a?.equals(b)?(b==null) |
| a!=b | !a?.equals(b)?(b==null) |
fun main(arg: Array<String>) {
val myClass1 = myClass(1, 2)
val myClass2 = myClass(1, 2)
val myClass3 = myClass(3, 4)
println(myClass1 == myClass2)
println(myClass3 == myClass2)
}
class myClass(a: Int, b: Int) {
private var a: Int = a
private var b: Int = b
operator fun compareTo(c: myClass): Int {
var m = this.a + this.b
var n = c.a + c.b
return m - n
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (javaClass != other?.javaClass) return false
other as myClass
if (a != other.a) return false
if (b != other.b) return false
return true
}
override fun hashCode(): Int {
var result = a
result = 31 * result + b
return result
}
}
