About this question
I understand that wrapper class is like a custom object that you can define in an Apex class but I am not sure why getter and setter methods are used for each field in a wrapper class. What is the purpose of it?
public with sharing class GetAllOpportunities { @AuraEnabled(cacheable=true) public static List getAllOpps() { List listOpp = [SELECT Id, Name ,StageName, CloseDate FROM Opportunity Order By Name asc]; List response = new List(); for(Opportunity opp : listOpp){ DataTableWrapper obj = new DataTableWrapper(); obj.oppId = opp.Id; obj.name = opp.Name; obj.nameUrl = '/'+opp.Id; obj.stageName = opp.StageName; obj.closeDate = opp.CloseDate; response.add(obj); } return response; } private class DataTableWrapper { @AuraEnabled public Id oppId {get;set;} @AuraEnabled public String name {get;set;} @AuraEnabled public String nameUrl {get;set;} @AuraEnabled public String stageName {get;set;} @AuraEnabled public Date closeDate {get;set;} } } 
