《Kotlin极简教程》第二章 Hello,World 函数函数

/**
 * We declare a package-level function main which returns Unit and takes
 * an Array of strings as a parameter. Note that semicolons are optional.
 */

fun main(args: Array<String>) {
    println("Hello, world!")
}

fun double(x: Int): Int {}

val result = double(2)

fun sum(a: Int, b: Int): Int { return a + b}

fun sum(a: Int, b: Int) = a + b

fun printSum(a: Int, b: Int): Unit { print(a + b)}

fun printSum(a: Int, b: Int) { print(a + b)}