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罗祥
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README.md
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## 十二、Scala ## 十二、Scala
1. [Scala简介及开发环境配置](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala简介及开发环境配置.md) 1. [Scala简介及开发环境配置](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala简介及开发环境配置.md)
2. 2. [基本数据类型和运算符](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala基本数据类型和运算符.md)
3. [Scala数组](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala数组相关操作.md)
4. [映射和元组](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala映射和元组.md)
5. [Scala集合](https://github.com/heibaiying/BigData-Notes/blob/master/notes/Scala集合.md)

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notes/Scala映射和元组.md
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# Scala映射和元组 # Scala映射和元组
<nav>
<a href="#一映射Map">一、映射(Map)</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#11-构造映射">1.1 构造映射</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#12-获取值">1.2 获取值</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#13-新增修改删除值">1.3 新增/修改/删除值</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#14-遍历映射">1.4 遍历映射</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#15-产生新映射">1.5 产生新映射</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#16-有序映射">1.6 有序映射</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#17-其他方法">1.7 其他方法</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#18-与Java互操作">1.8 与Java互操作</a><br/>
<a href="#二元组Tuple">二、元组(Tuple)</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#21--模式匹配">2.1 模式匹配</a><br/>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#22-Zip方法">2.2 Zip方法</a><br/>
</nav>
## 一、映射(Map) ## 一、映射(Map)
### 1.1 构造映射 ### 1.1 构造映射
```scala ```scala
scala> import scala.collection.immutable.HashMap
import scala.collection.immutable.HashMap
// 初始化一个空map // 初始化一个空map
scala> val scores01 = new HashMap[String, Int] val scores01 = new HashMap[String, Int]
scores01: scala.collection.immutable.HashMap[String,Int] = Map()
// 从指定的值初始化映射（方式一） // 从指定的值初始化映射（方式一）
scala> val scores02 = Map("hadoop" -> 10, "spark" -> 20, "storm" -> 30) val scores02 = Map("hadoop" -> 10, "spark" -> 20, "storm" -> 30)
scores02: scala.collection.immutable.Map[String,Int] = Map(hadoop -> 10, spark -> 20, storm -> 30)
// 从指定的值初始化映射（方式二） // 从指定的值初始化映射（方式二）
scala> val scores03 = Map(("hadoop", 10), ("spark", 20), ("storm", 30)) val scores03 = Map(("hadoop", 10), ("spark", 20), ("storm", 30))
scores03: scala.collection.immutable.Map[String,Int] = Map(hadoop -> 10, spark -> 20, storm -> 30)
``` ```
采用上面方式得到的都是不可变(immutable)映射，想要得到可变映射，则用： 采用上面方式得到的都是不可变(immutable)映射，想要得到可变映射，则用：
```scala ```scala
scala> val scores04 = scala.collection.mutable.Map("hadoop" -> 10, "spark" -> 20, "storm" -> 30) val scores04 = scala.collection.mutable.Map("hadoop" -> 10, "spark" -> 20, "storm" -> 30)
scores04: scala.collection.mutable.Map[String,Int] = Map(spark -> 20, hadoop -> 10, storm -> 30)
``` ```
### 1.2 获取值 ### 1.2 获取值
@@ -58,10 +66,10 @@ object ScalaApp extends App {
// 2.如果key不存在则新增 // 2.如果key不存在则新增
scores("flink") = 40 scores("flink") = 40
// 3.可以通过+=来进行多个更新或新增操作 // 3.可以通过 += 来进行多个更新或新增操作
scores += ("spark" -> 200, "hive" -> 50) scores += ("spark" -> 200, "hive" -> 50)
// 4.可以通过-= 来移除某个键和值 // 4.可以通过 -= 来移除某个键和值
scores -= "storm" scores -= "storm"
for (elem <- scores) {println(elem)} for (elem <- scores) {println(elem)}