• Scala Map集合


    package com.wyh.day01
    
    object ScalaMap {
      def main(args: Array[String]): Unit = {
        /**
          * 不可变Map
          *
          */
        //创建不可变集合,两种写法
        var map1 = Map((1604093026, "王友虎"), 1604093029 -> "赵以浩")
    
        //通过key获取到Option
        var res1 = map1.get(1604093026)
        //通过get获取到具体的值
        println(res1.get)
    
        //获取key对应的value值,如果没有,返回指定的默认值
        println(map1.getOrElse(16044, "默认值"))
        println(map1.getOrElse(1604093029, "默认值"))
    
        //获取不存在的key返回None
        println(map1.get(123456))
        println("=" * 100)
    
        //遍历Map
        for (elem <- map1) {
          var key = elem._1
          var value = elem._2
          println(key + "	" + value)
        }
    
        println("=" * 100)
    
        //添加元素,可以同时添加多个元素,返回一个新的Map
        val map2 = map1 + ((1604093002, "小李"), 16044 -> "xiaoxiao")
        for (elem <- map2) {
          var key = elem._1
          var value = elem._2
          println(key + "	" + value)
        }
    
        /**
          *
          * 可变Map
          */
    
        import scala.collection.mutable
    
        var map4 = mutable.Map(("品牌", "小米"), "型号" -> "小米6")
    
        val value = map4("品牌")
        println(value)
    
        println("=" * 100)
    
        var map5 = mutable.Map[String, Int]()
    
        //往其中添加元素
        map5.put("学生1", 12138)
        map5.put("学生2", 15478)
        map5.put("学生3", 11438)
        map5.put("学生4", 17138)
    
        val i = map5.getOrElse("xue", 1)
        println(i)
    
        for (elem <- map5) {
          var key = elem._1
          var value = elem._2
          println(key + "	" + value)
        }
    
    
        val values = map5.values
        for (elem <- values) {
          println(elem)
        }
    
      }
    }
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  • 原文地址:https://www.cnblogs.com/wyh-study/p/12217601.html
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