Java List获取集合中的最大值或最小值

1.List集合中的元素为基本类型，我们可以使用java.util中的Collections提供的方法，来取出最大值或者最小值。（1）Integer类型

package com.yuxuange.study.test;import java.util.*;public class Test {public static void main(String[] args) {List list = new LinkedList();list.add(99);list.add(54);list.add(82);list.add(12);list.add(33);list.add(79);list.add(90);list.add(7);list.add(66);list.add(38);list.add(7);System.out.println(list.toString());Integer max = Collections.max(list);System.out.println("集合中最大值为：" + max);Integer min = Collections.min(list);System.out.println("集合中最小值为：" + min);}}

输出的结果为：整型输出结果（2）Double类型

package com.yuxuange.study.test;import java.util.*;public class Test {public static void main(String[] args) {List list = new LinkedList();list.add(97.42);list.add(83.555);list.add(99.8045);list.add(45.33);list.add(8.2006);list.add(54.333);list.add(72.9055);list.add(56.999997);list.add(20.9);list.add(6.099912);System.out.println(list.toString());Double max = Collections.max(list);System.out.println("集合中最大值为：" + max);Double min = Collections.min(list);System.out.println("集合中最小值为：" + min);}}

输出结果为： Double类型输出结果 2.List集合中的元素为引用类型时（1）String类型

package com.yuxuange.study.test;import java.util.*;public class Test {public static void main(String[] args) {List list = new LinkedList();list.add("97.435");list.add("92");list.add("80.3455");list.add("10.9833");list.add("52");list.add("35.663444");list.add("79.0");list.add("42");list.add("83.482");list.add("26.454448");System.out.println(list.toString());String max = Collections.max(list);System.out.println("集合中最大值为：" + max);String min = Collections.min(list);System.out.println("集合中最小值为：" + min);}}

String类型输出结果

（2）对象，比如有个对象集合，集合中保存了学生的对象信息，我们要根据学号，年龄等字段找出对应的最大值或者最小值

package com.yuxuange.study.test;import java.util.*;public class Test {public static void main(String[] args) {List list = new LinkedList();Student zhangsan = new Student(99, "张三", 28, 96.0);Student lisi = new Student(82, "李四", 25, 89.0);Student wangwu = new Student(26, "王五", 23, 72.5);Student zhaoliu = new Student(68, "赵六", 30, 65.5);Student tianqi = new Student(8, "田七", 26, 100.0);Student fengba = new Student(47, "冯八", 21, 52.5);Student jinjiu = new Student(14, "金九", 27, 46.5);list.add(zhangsan);list.add(lisi);list.add(wangwu);list.add(zhaoliu);list.add(tianqi);list.add(fengba);list.add(jinjiu);System.out.println(list.toString());Student noMax = list.stream().max(Comparator.comparing(Student::getNo)).get();Student noMin = list.stream().min(Comparator.comparing(Student::getNo)).get();System.out.println("集合中学号最大的学生信息为" + noMax);System.out.println("集合中学号最小的学生信息为" + noMin);Student ageMax = list.stream().max(Comparator.comparing(Student::getAge)).get();Student ageMin = list.stream().min(Comparator.comparing(Student::getAge)).get();System.out.println("集合中年龄最大的学生信息为" + ageMax);System.out.println("集合中年龄最小的学生信息为" + ageMin);}}class Student {private Integer no;private String name;private Integer age;private Double score;public Student(Integer no, String name, Integer age, Double score) {this.no = no;this.name = name;this.age = age;this.score = score;}public Integer getNo() {return no;}public void setNo(Integer no) {this.no = no;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getAge() {return age;}public void setAge(Integer age) {this.age = age;}public Double getScore() {return score;}public void setScore(Double score) {this.score = score;}@Overridepublic String toString() {return "Student{" +"no=" + no +", name='" + name + '\'' +", age=" + age +", score=" + score +'}';}}

输出结果为：对象类型输出结果

云奕文章网

Java List获取集合中的最大值或最小值

相关推荐：