获取List集合中的最大值和最小值

女爷i 2024-03-16 14:07 73阅读 0赞

## 获取List集合中的最大值和最小值 ##

### Collections ###

#### String、Integer、Double类型 ####

*  当List中元素为String、Integer、Double类型时，可以使用Collections类中的 max 和 min 方法直接获取最大值和最小值；
 *      public static void main(String[] args) {
                List<String> stringList = new ArrayList<>();
                stringList.add("10");
                stringList.add("34");
                stringList.add("67");
                stringList.add("84");
                stringList.add("1");
                System.out.println("（String类型）最大值=" + Collections.max(stringList));
                System.out.println("（String类型）最小值=" + Collections.min(stringList));
         
                List<Integer> integerList = new ArrayList<>();
                integerList.add(5);
                integerList.add(38);
                integerList.add(52);
                integerList.add(88);
                integerList.add(100);
                System.out.println("（Integer类型）最大值=" + Collections.max(integerList));
                System.out.println("（Integer类型）最小值=" + Collections.min(integerList));
         
                List<Double> doubleList = new ArrayList<>();
                doubleList.add(1.5);
                doubleList.add(45.6);
                doubleList.add(88.08);
                doubleList.add(55.2);
                doubleList.add(100.01);
                System.out.println("（Double类型）最大值=" + Collections.max(doubleList));
                System.out.println("（Double类型）最小值=" + Collections.min(doubleList));
            }
 *  ![\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-CEPJfcYh-1686095887125)(C:\\Users\\quyanliang\\AppData\\Roaming\\Typora\\typora-user-images\\1686095772629.png)\]][img-CEPJfcYh-1686095887125_C_Users_quyanliang_AppData_Roaming_Typora_typora-user-images_1686095772629.png]
 *  \*\*注意：\*\*当List元素因为类型为String时，可能会出现以下问题；
 *  当最大值为10或10的倍数时不生效，为最小值时生效；
 *  ![\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-eAFD4APH-1686095887126)(C:\\Users\\quyanliang\\AppData\\Roaming\\Typora\\typora-user-images\\1686095794630.png)\]][img-eAFD4APH-1686095887126_C_Users_quyanliang_AppData_Roaming_Typora_typora-user-images_1686095794630.png]
 *  当元素数据全部为10或10的倍数时，最大值和最小值均生效；
 *  ![\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-n1jIVEIQ-1686095887126)(C:\\Users\\quyanliang\\AppData\\Roaming\\Typora\\typora-user-images\\1686095812798.png)\]][img-n1jIVEIQ-1686095887126_C_Users_quyanliang_AppData_Roaming_Typora_typora-user-images_1686095812798.png]

#### 对象类型 ####

*  当List中元素为对象时，比如想要获取年龄最大和最小人的信息；
 *  ![\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-r7TQjHeS-1686095887126)(C:\\Users\\quyanliang\\AppData\\Roaming\\Typora\\typora-user-images\\1686095833166.png)\]][img-r7TQjHeS-1686095887126_C_Users_quyanliang_AppData_Roaming_Typora_typora-user-images_1686095833166.png]

### 排序 ###

#### Integer类型 ####

*  当List元素类型为Integer时可以使用排序，比如使用冒泡排序将List元素按照从大到小排序，然后取List的第一个和最后一个元素获取最大值和最小值；
 *  ![\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-PdvBjCqk-1686095887127)(C:\\Users\\quyanliang\\AppData\\Roaming\\Typora\\typora-user-images\\1686095864074.png)\]][img-PdvBjCqk-1686095887127_C_Users_quyanliang_AppData_Roaming_Typora_typora-user-images_1686095864074.png]

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