数组排序 #yyds干货盘点#

示例1：基本类型数组排序

public static void main(String[] args) {//psvm
        String[] data = {"zhangsan", "lii", "wanger","wangsan321" ,"qian321qi","maiz2i", "qianwu"};
        //Arrays 数组工具类
        Arrays.sort(data); //默认按照字典顺序进行排序
        for (String item : data){
            System.out.println(item);
        }
        System.out.println("-------内部类-------");
        String[]  data2 = {"zhangsan", "lii", "wanger","wangsan321" ,"qian321qi","maiz2i", "qianwu"};
        class AA implements Comparator<String> {
            @Override
            public int compare(String o1, String o2) {
                return o1.length()-o2.length();
            }
        }
        AA aa = new AA();
        Arrays.sort(data2,aa);
        for (String item : data2){
            System.out.println(item);
        }
        System.out.println("------匿名内部类--------");
        String[]  data3 = {"zhangsan", "lii", "wanger","wangsan321" ,"qian321qi","maiz2i", "qianwu"};
        Arrays.sort(data3, new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                return o1.length()- o2.length();
            }
        });
        for (String item : data3){
            System.out.println(item);
        }
        System.out.println("------Lambda表达式--------");
        String[]  data4 = {"zhangsan", "lii", "wanger","wangsan321" ,"qian321qi","maiz2i", "qianwu"};
        Arrays.sort(data4,(o1,o2)->o1.length()-o2.length());
        Stream.of(data4).forEach(System.out::println);//JAVA8流
    }

示例2：对象数组排序

• 实体类

  public class Stu {
  private int id;
  private String name;
  private float score;
  public Stu() {
  }
  public Stu(int id, String name,   float score) {
      this.id = id;
      this.name = name;
      this.score = score;
  }
  public int getId() {
      return id;
  }
  public void setId(int id) {
      this.id = id;
  }
  public String getName() {
      return name;
  }
  public void setName(String name) {
      this.name = name;
  }
  public float getScore() {
      return score;
  }
  public void setScore(float score) {
      this.score = score;
  }
  @Override
  public String toString() {
      return "Stu{" +
              "id=" + id +
              ", name='" + name + '\'' +
              ", score=" + score +
              '}';
  }
  }

• 测试代码

  public static void main(String[] args) {//psvm
  Stu zhangsan = new Stu(1001, "zhangsan", 88.8f);
  Stu lisi = new Stu(1007, "lisi", 68.8f);
  Stu wanger = new Stu(1005, "wanger", 98.8f);
  Stu mazi = new Stu(1004, "mazi", 88.8f);
  Stu qianwu = new Stu(1002, "qianwu", 78.8f);
  
  //按学号排
  Stu[] data1 = {zhangsan,lisi,wanger,mazi,qianwu};
  Arrays.sort(data1, new Comparator<Stu>() {
      @Override
      public int compare(Stu o1, Stu o2) {
          return o1.getId()-o2.getId();
      }
  });
  for (Stu stu : data1) {
      System.out.println(stu);
  }
  //按名称降序排
  System.out.println("-----------------");
  Stu[] data2 = {zhangsan,lisi,wanger,mazi,qianwu};
  Arrays.sort(data2,(o1,o2)->o2.getName().compareTo(o1.getName()));;
  Stream.of(data2).forEach(System.out::println);
  //按学号降序排，如果成绩相同按名称长短降序排
  System.out.println("-----------------");
  Stu zhaoliu = new Stu(1004, "zhaoliu", 88.8f);
  Stu liusong = new Stu(1002, "liusong", 78.8f);
  Stu[] data3 = {zhangsan,lisi,zhaoliu,liusong,wanger,mazi,qianwu};
  /*
  Arrays.sort(data3, new Comparator<Stu>() {
      @Override
      public int compare(Stu stu1, Stu stu2) {
          if(stu1.getId() != stu2.getId()){
              return stu1.getName().length()-stu2.getName().length();
          }else {
              return stu1.getId()-stu2.getId();
          }
      }
  });
  */
  Arrays.sort(data3,(stu1,stu2)->{
      if(stu1.getId() != stu2.getId()){
          return stu1.getName().length()-stu2.getName().length();
      }else {
          return stu1.getId()-stu2.getId();
      }
  });
  Stream.of(data3).forEach(System.out::println);
  }