循环语法

pom.xml

@@ -1,4 +1,5 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>top.fjy8018</groupId>
     <artifactId>helloscala</artifactId>
@@ -19,6 +20,7 @@
         <maven.compiler.target>1.8</maven.compiler.target>
         <encoding>UTF-8</encoding>
         <scala.version>2.11.8</scala.version>
+        <spark.version>2.3.1</spark.version>
     </properties>
 
     <dependencies>
@@ -27,6 +29,20 @@
             <artifactId>scala-library</artifactId>
             <version>${scala.version}</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.apache.spark</groupId>
+            <artifactId>spark-core_2.11</artifactId>
+            <version>${spark.version}</version>
+        </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.apache.spark/spark-sql -->
+        <dependency>
+            <groupId>org.apache.spark</groupId>
+            <artifactId>spark-sql_2.11</artifactId>
+            <version>2.3.1</version>
+        </dependency>
+
     </dependencies>
 
     <build>
@@ -45,7 +61,6 @@
                         </goals>
                         <configuration>
                             <args>
-                <arg>-make:transitive</arg>
                                 <arg>-dependencyfile</arg>
                                 <arg>${project.build.directory}/.scala_dependencies</arg>
                             </args>

src/main/scala/top/fjy8018/scala/FunctionApp.scala

@@ -12,6 +12,17 @@ object FunctionApp {
 
     // 调用无参方法可以不加括号
     printHello
+
+    printHello("scala")
+
+    // 调用带默认值的方法不可以不加括号
+    defaultParam()
+    defaultParam("new value")
+
+    // 支持自定义参数顺序
+    println(sum(y = 2,x = 1))
+
+    printAllInt(1,2,3,4,5,6)
   }
 
   def add(x:Int,y:Int):Int={
@@ -29,4 +40,27 @@ object FunctionApp {
 
   def printHello()= println("Hello world!")
 
+  /**
+    * 支持函数重载
+    * @param n
+    */
+  def printHello(n:String)=println("Hello world " + n)
+
+  /**
+    * 支持参数默认值
+    * @param n
+    */
+  def defaultParam(n:String="defaultValue")=println("value:" + n)
+
+  /**
+    * 可变参数
+    * @see org.apache.spark.sql.Dataset#select(org.apache.spark.sql.TypedColumn, org.apache.spark.sql.TypedColumn, org.apache.spark.sql.TypedColumn, org.apache.spark.sql.TypedColumn, org.apache.spark.sql.TypedColumn)
+    * @param numbers
+    */
+  def printAllInt(numbers:Int*): Unit ={
+    for (number <- numbers){
+      print(number +",")
+    }
+  }
+
 }

src/main/scala/top/fjy8018/scala/Loop.scala

@@ -0,0 +1,70 @@
+package top.fjy8018.scala
+
+/**
+  * F嘉阳
+  * 2018-11-26 17:03
+  */
+object Loop {
+  val list = Array("a","b","c","d")
+
+  def main(args: Array[String]): Unit = {
+    printTest
+    println()
+    loop1
+    println()
+    loop2()
+    println()
+    loop3
+    println()
+    rangeTest1
+    rangeTest2
+    sumTest
+  }
+
+  def printTest()=print(1 to 10)
+
+  def loop1(): Unit ={
+    for (l <- list){
+      print(l)
+    }
+  }
+
+  /**
+    * 类似java lambda函数表达式
+    */
+  def loop2(): Unit ={
+    list.foreach(l => print(l))
+  }
+
+  /**
+    * 带条件循环表达式
+    */
+  def loop3(): Unit ={
+    for (i<- 1 to 10 if i%2==0){
+      print(i+" ")
+    }
+  }
+
+  def rangeTest1(): Unit ={
+    // 指定步长，Range为to函数的底层实现
+    print(Range(1,10,2))
+    println()
+    println(Range(10,1,-3))
+  }
+
+  /**
+    * until 左闭右开，to左闭右闭
+    */
+  def rangeTest2(): Unit ={
+    println(1 until 10)
+  }
+
+  def sumTest(): Unit ={
+    var (num,sum) = (100,0)
+    while (num>0){
+      sum += num
+      num -= 1
+    }
+    println(sum)
+  }
+}