大数据学习之SCALA分布式语言三

7.集合类

111.可变set一

112.可变set二

113.不可变MAP集合一

114.不可变MAP集合二

115.不可变MAP集合三

116.可变map一

package com . itbaizhan . chapter07

//TODO 2. 使用 mutable.Map 前导入如下包

import scala . collection . mutable

// 可变 Map 集合 object MapMutable extends App {

//TODO 1. mutable.Map 表示可变的 Map 集合

val map1 = mutable . Map ( 1 -> " 刘备 " , 2 -> " 关

羽 " , 3 -> " 张飞 " )

val map2 = mutable . Map ( 6 -> " 曹操 " , 7 -> " 许

褚 " , 8 -> " 夏侯渊 " )

//TODO 3. 添加键值对元素 , 原 Map 集合对象改变

map1 . put ( 4 , " 赵云 " )

println ( "put 后 map1:" + map1 . mkString ( "," ))

//TODO 4. + 添加键值对不改变原集合

val map3 : mutable . Map [ Int , String ] = map1 +

( 5 -> " 凤雏 " )

println ( "+ 后 map1:" + map1 . mkString ( "," ))

println ( "+ 后 map3:" + map3 . mkString ( "," ))

println ( map1 eq map3 ) //false

//TODO 5. += 添加键值对改变原集合 , 并返回修改后 Map 对

象的地址

val map4 : mutable . Map [ Int , String ] = map1 +=

( 5 -> " 凤雏 " )

println ( "+= 后 map1:" + map1 . mkString ( "," ))

println ( "+= 后 map4:" + map4 . mkString ( "," ))

println ( map1 eq map4 ) //true

//TODO 6. 修改 key 对应的 value

map1 . update ( 1 , " 刘玄德 " )

println ( "update 后 map1:" + map1 . mkString ( "," ))

map1 ( 1 ) = " 刘备 "

println ( "update 后 map1:" + map1 . mkString ( "," ))

//TODO 7. 删除数据

map1 . remove ( 1 )

println ( "remove 后 map1:" + map1 . mkString ( "," ))

// - 不改变原 Map 集合

val map5 : mutable . Map [ Int , String ] = map1 - 2  

println ( "map1 - 2 后 map1:" +