Several ways of lambda used in functions in kotlin (higher-order functions)

//Kotlin Used in functions in lambda Several ways 
fun main(args: Array<String>) {
    /**
     *    The return type in the function has lambda
     */
    //            First step ： Declaration of function input and output            The second step ： Implementation of declarative functions 
    val methodAction1: (Int, Int, Int) -> String = { number1, number2, number3 ->
        val inputValue = 99999
        "$inputValue yuknight  Parameter one :$number1, Parameter two :$number2,  Parameter 3 :$number3"
    }
    // The third step ： Call this function 
    println(methodAction1(2, 4, 6))
    /*----------------------------------------------------*/
    val methodAction4: (String) -> String = { "$it yuknight" }
    println(methodAction4("kotlin"))
    /*----------------------------------------------------*/
    // Type inference of anonymous functions 
    // Anonymous functions ： The type is inferred as String
    // Method name ：   Must specify   Parameter type   and   Return type 
    // Method name  =   Type inference return type 
    val methodAction6 = { v1: Double, v2: Float, v3: Int ->
        "v1:$v1, v2:$v2, v3:$v3"
    }//methodAction6  function  ：(Double, Float, Int)->String
    println(methodAction6(22.3, 34.3f, 77))

    val method1 = { 3.14f } //method1  function ：()->Float
    println(method1())

    val method2 = { number: Int -> number }//method2  function ：（Int）->Int
    println(method2(88))

    /*----------------------------------------------------*/
    /**
     *    There are in the parameters of the function lambda
     */
    //lambda The return value of the function is String
    val serverResponse1 = { responseMsg: String, responseCode: Int ->
        println(
            "lambda The return value of the function is String  The result is ：responseMsg:$responseMsg, responseCode:$responseCode"
        )
        "lambda The return value of the function is String  The result is ：responseMsg:$responseMsg, responseCode:$responseCode"
//        println(" The final result of getting the server response is ：responseMsg:$responseMsg, responseCode:$responseCode")

    }
    doLogin11("yuknight", "123456", serverResponse1)
    /*----------------------------------------------------*/
    doLogin11("yuknight", "123456") { responseMsg: String, responseCode: Int ->
        println("lambda The return value of the function is String  The result is ：responseMsg:$responseMsg, responseCode:$responseCode")
        "lambda The return value of the function is String  The result is ：responseMsg:$responseMsg, responseCode:$responseCode"
    }

    /**
     *    There are lambda
     */
    val lambdaActionFun = { msg: String, code: Int ->
        "msg:$msg, code:$code"
    }
    val lambdaActF = lambdaFun("yuknight", 200, lambdaActionFun)
    val lambdaStrF = lambdaActF(" Return value ", 300)
    println("lambdaStr:$lambdaStrF")
    //
    val lambdaAct = lambdaFun("yuknight", 200) { msg: String, code: Int ->
        "msg:$msg, code:$code"
    }
    val lambdaStr = lambdaAct(" Return value ", 300)
    println("lambdaStr:$lambdaStr")
    //
    val lambdaFunStr = lambdaFun("yuknight", 200) { msg: String, code: Int ->
        "msg:$msg, code:$code"
    }(" Return value ", 300)
    println("lambdaFunStr:$lambdaFunStr")
}

fun doLogin11(userName: String, userPwd: String, serverResponse: (String, Int) -> String) {
    if (DB_SAVE_USER_NAME == userName && DB_SAVE_USER_PWD == userPwd) {
        val serverResponseResult = " Congratulations , Login successful ！"
        serverResponse(serverResponseResult, 200)
    } else {
        val serverResponseResult = " I'm sorry , Login failed ！"
        serverResponse(serverResponseResult, 404)
    }
}

fun lambdaFun(str1: String, int1: Int, lambdaAction: (String, Int) -> String): (String, Int) -> String {
    lambdaAction(str1, int1)
    return { str1, int1 -> "str1:$str1, int1:$int1" }
}