lambda表达式操作集合数据（下）

//4.Stream中常见的api操作

    List<String> accountList = new ArrayList<>();
    accountList.add("songjiang");
    accountList.add("lujinyi");
    accountList.add("wuyong");
    accountList.add("linchong");
    accountList.add("luzhishen");
    accountList.add("likui");
    accountList.add("wusong");
//1.map中间操作，map()方法接受一个Functional接口
    accountList = accountList.stream().map(x -> "梁山好汉" + x).collect(Collectors.toList());
    accountList.forEach(System.out::println);
//2.fiilter()添加过滤条件，过滤符合条件的用户
    accountList = accountList.stream().filter(x -> x.length() > 5).collect(Collectors.toList());
    accountList.forEach(System.out::println);
//3.foreach 增强for循环
    accountList.forEach(x-> System.out.println("foreach->"+x));
    accountList.forEach(x-> System.out.println("foreach->"+x));
    accountList.forEach(x-> System.out.println("foreach->"+x));
//4.peek()中间操作，迭代数据完成数据的一次处理过程
    accountList.stream().peek(x -> System.out.println("peek1" + x))
        .peek(x -> System.out.println("peek2" + x)).forEach(
        System.out::println
    );
    //5.Stream中对数字运算符的支持
    List<Integer> integers = new ArrayList<>();
    integers.add(1);
    integers.add(221);
    integers.add(111);
    integers.add(11);
    integers.add(123);
    integers.add(1889);
    integers.add(132232);
    integers.add(3242);
    //1.skip()中间操作，有状态，跳过部分数据
    List<Integer> integerList = integers.stream().skip(3).collect(Collectors.toList());
    integerList.forEach(System.out::println);
    //2.limit()操作，有状态，限制输出数据量
    List<Integer> integerList = integers.stream().skip(3).limit(2).collect(Collectors.toList());
    integerList.forEach(System.out::println);
    //3.distinct去除重复的数据
    List<Integer> integerList = integers.stream().distinct().collect(Collectors.toList());
    integerList.forEach(System.out::println);
    //4.sort排序操作
    List<Integer> integerList = integers.stream().sorted((x,y)->x-y).collect(Collectors.toList());
    integerList.forEach(System.out::println);
    //5.max min获取最大最小值
    Optional<Integer> optional = integers.stream().max((x, y) -> x - y);
    System.out.println(optional.get());
    //6.reduce()合并处理数据
    Optional<Integer> reduce = integers.stream().reduce((sum, x) -> sum + x);
    System.out.println(reduce.get());
  }
来源：CSDN
作者：文泽稳
链接：https://blog.csdn.net/qq_31162311/article/details/104001223
标签
lambda表达式