第8节：scala常用集合Map和Tuple

package basicsobject HelloMapTuple {  def main(args: Array[String]): Unit = {    var bigdatas = Map("Spark" -> 6, "Hadoop" -> 11)    //bigdatas("Spark")=10直接构造的map是不可变的，一旦改变就变成新的内容，原有内容保持不变    println(bigdatas.apply("Spark"))    val progran = scala.collection.mutable.Map("Spark" -> 15, "java" -> 15)    progran("Spark") = 10    for ((key, age) <- progran) println("key--"+key+":" + age)    val progranhashmap = new scala.collection.mutable.HashMap[String, Int]    progranhashmap.put("spk", 11)    print(progranhashmap.getOrElse("Python","is null")) //为了不报异常或者提供默认值    val person = Map(("zyl", 28), ("dtspark", 1))    //    println(person.getOrElse("zyl", "dtspark"))    progranhashmap += ("Spark" -> 6, "Hadoop" -> 11)    // progranhashmap -= ("java")    for (key <- progranhashmap.keySet) println(key)    for (value <- progranhashmap.values) println(value)    for ((name, age) <- progranhashmap) yield (age, name)    println("----------------------------1")    for ((name, age) <- progranhashmap) println(name + ":" + age)    println("----------------------------2")    //排序，默认会按照key的字母首字母排序    val sortMap = scala.collection.immutable.SortedMap(("eyl", 28), ("ftspark", 100))    for ((name, age) <- sortMap) println(name + ":" + age)    println("----------------------------*********")    //LinkedHashMap可以记住元素插入的顺序    val linkedhashmap = new scala.collection.mutable.LinkedHashMap[String, Int]    linkedhashmap += ("Spark" -> 6, "Hadoop" -> 11, "java" -> 12)    for ((name, age) <- linkedhashmap) println(name + ":" + age)    println()    val tuple=("zyl",28,"java","I am  into spark so much!!")    //tuple从1k开始索引，tuple中可以有很多不同类型的数据    println(tuple._3)  }}

打印结果：

6
key--java:15
key--Spark:10
is nullspk
Hadoop
Spark
11
11
6
----------------------------1
spk:11
Hadoop:11
Spark:6
----------------------------2
eyl:28
ftspark:100
----------------------------*********
Spark:6
Hadoop:11
java:12
java