函数定义
```scala
def max(x: Int, y: Int): Int = {
if (x > y)
x
else
y
}
```
```scala
def 方法名(参数名: 参数类型): 返回值类型 = {
// 方法体
// 最后一行为返回值，不需要 return
}
```
调用无参方法可省略括号
```scala
object Person {
def main(args: Array[String]): Unit = {
sayNameAgain
}
def sayNameAgain(): Unit ={
println("Apollo")
}
}
```
默认参数
```scala
object Person {
def main(args: Array[String]): Unit = {
sayName()
sayName("Apollo")
}
def sayName(name: String = "Default_Name"): Unit = {
println(name)
}
}
```
命名参数
```scala
object Person {
def main(args: Array[String]): Unit = {
println(getSpeed(10, 2))
println(getSpeed(distance = 10, time = 2))
println(getSpeed(time = 2, distance = 10))
}
def getSpeed(distance: Float, time: Float): Float = {
distance / time
}
}
```
可变参数
```scala
object Person {
def main(args: Array[String]): Unit = {
println(sum(10, 2))
println(sumPlus(1, 2, 3, 4, 5, 6, 7, 8))
}
def sum(a: Int, b: Int): Int = {
a + b
}
def sumPlus(numbers: Int*): Int = {
var result = 0;
for (number <- numbers) {
result += number
}
result
}
}
```
条件表达式
```scala
object Person {
def main(args: Array[String]): Unit = {
val x = 100
val res = if (x > 10)//可以赋值
true
else
false
println(res)
}
}
```
循环表达式
```scala
object Person {
def main(args: Array[String]): Unit = {
println(1 to 10)
println(1.to(10))
}
}
```
```
Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
Range(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)
```
```scala
object Person {
def main(args: Array[String]): Unit = {
println(1 until 10)
println(1.until(10))
}
}
```
```
Range(1, 2, 3, 4, 5, 6, 7, 8, 9)
Range(1, 2, 3, 4, 5, 6, 7, 8, 9)
```
```scala
for (i <- 1 to 10) {
println(i)
}
for (i <- 1 to 10 if i % 2 == 0) {
println(i)
}
```
```scala
val team = Array("Apollo", "Paul", "Tom", "Amy")
for (person <- team){
println(person)
}
```
```scala
val team = Array("Apollo", "Paul", "Tom", "Amy")
team.foreach(person => println(person))
```
