groupingby

问题 I have a list of Student Objects as below. Student1 DOB : 12/02/2010 Student2 DOB : 12/03/2010 Student1 DOB : 12/04/2010 Student4 DOB : Student2 DOB : Student3 DOB : 12/01/2010 Student{ String name; Date dob; } I want to group the Students based on the DOB as below. All Students should be grouped based on the student name. Students must be in descending order of dob. Same Students grouped together should be in descending order of dob. Remaining Student objects must be in same order as it is

问题 I have a list of Student Objects as below. Student1 DOB : 12/02/2010 Student2 DOB : 12/03/2010 Student1 DOB : 12/04/2010 Student4 DOB : Student2 DOB : Student3 DOB : 12/01/2010 Student{ String name; Date dob; } I want to group the Students based on the DOB as below. All Students should be grouped based on the student name. Students must be in descending order of dob. Same Students grouped together should be in descending order of dob. Remaining Student objects must be in same order as it is

问题 I have a List of Procedure objects as below Procedure1 01/01/2020 Procedure2 03/01/2020 Procedure3 03/01/2020 Procedure1 04/01/2020 Procedure5 05/01/2020, 02/01/2020 Procedure2 06/01/2020 and my Procedure class is like Class Procedure { List<Date> procedureDate; String procedureName; } I want to sort and group the objects based on the below conditions. All procedures should be grouped based on the procedure name. Procedures must be in descending order of procedure date. [first element in date

问题 I have a List of Procedure objects as below Procedure1 01/01/2020 Procedure2 03/01/2020 Procedure3 03/01/2020 Procedure1 04/01/2020 Procedure5 05/01/2020, 02/01/2020 Procedure2 06/01/2020 and my Procedure class is like Class Procedure { List<Date> procedureDate; String procedureName; } I want to sort and group the objects based on the below conditions. All procedures should be grouped based on the procedure name. Procedures must be in descending order of procedure date. [first element in date