初学scala

package com.lv.test

import java.io.IOException
import java.io.FileNotFoundException
import java.io.FileReader
import java.io.PrintWriter
import java.io.File
import scala.io.Source

/**
* scala 初学
* @author lv
*/
object hello {

def main(args: Array[String]) {
//变量使用
var a = 1;
var b = 2;
var c = a + b;
println(c)
//循环
var i = 0;
for (i <- 1 to 3) {
println(i)
}
//集合使用
var index = 0
val numberList = List(1, 2, 3, 4, 5) // val 只能赋值一次
for (index <- numberList) {
println(index);
}
//函数
def printMe(): Unit = {
println("hello scala");
}
def sum(a: Int, b: Int): Int = {
var sum: Int = 0
sum = a + b
return sum
}
printMe
println(sum(10, 5))
//调用同一个包下面的类
val pt = new scalaClassTest(5, 6)
pt.move(7, 8)
//Tuples
val t = new Tuple3(1, "hello", Console)
println(t._1)
println(t._2)
println(t._3)

//trait 类的继承
var pet: Friendly = new Dog
println(pet.greet())

pet = new HungryDog
println(pet.greet())

pet = new Dog with ExclamatoryGreeter
println(pet.greet())

pet = new HungryDog with ExclamatoryGreeter
println(pet.greet())
//异常
try {
val f = new FileReader("input.txt")
} catch {
case ex: FileNotFoundException => {
println("Missing file exception")
}
case ex: IOException => {
println("IO Exception")
}
}
//文件读写
val writer = new PrintWriter(new File("test.txt" ))

writer.write("Hello Scala")
writer.close()

Source.fromFile(new java.io.File("test.txt")).getLines().foreach(println)

}
}