public with sharing class Addresses extends SObjectDomain{

    public Addresses(List<SObject> sObjectList) {
        super(sObjectList);
    }

    public class Constructor implements SObjectDomain.IConstructable{
        public SObjectDomain construct(List<SObject> sObjectList){
            return new Addresses(sObjectList);
        }
    }

    public override void onApplyDefaults(){}

    public override void onBeforeInsert(){
      AddressService.translateCountryToISO2((Address__c[]) records);
    }

    public override void onAfterInsert(){
      AddressService.updateParentSyncStatus((Address__c[]) records, null);
    }

    public override void onBeforeUpdate(Map<Id,SObject> existingRecords) {
      AddressService.translateCountryToISO2((Address__c[]) records);
    }

    public override void onAfterUpdate(Map<Id,SObject> existingRecords) {
      AddressService.updateParentSyncStatus((Address__c[]) records, (Map<Id, Address__c>) existingRecords);
    }
}

public class printpdf {
    public List<QuoteLineItem> prd{get;set;}
    private final ApexPages.StandardController theController;
    
    public printpdf(ApexPages.StandardController controller) {
        theController = controller;
        
    prd = [Select Id , QuoteId, Product2Id, Product2.Name, Product2.Description, Product2.ProductCode, Product2.Cross_Distr_Channel_Status__c, Product2.GB_Enterprise_Prod_Hier_Level_5__c from QuoteLineItem where QuoteId=:thecontroller.getId()];
    }
}

I have created a custom email field on account object.
I want that when ever i create a new contact which uses account object in account field should use the account email field to fill in contact email field.

I am a newbie and just wanna practice. 

Thanks in advance fir all your suggestions. 

I want to create a validation rule in the account object.
I have two text data type fields. I have tried with workflow it is working fine but need a validation rule for this.

When field "Location" is changed, I want "Status" field equal to "Moved".

Please guide me on this. Thanks for help.

I have a custom tab(Report) on my account object. I have VF Page linked in the tab. I want that when I click over the tab it opens my VF Page in a new browser window.
Can anyone please help me as I am new to salesforce.

I want to create a validation rule in the account object.
I have two text data type fields. I have tried with workflow it is working fine but need a validation rule for this.

When field "Location" is changed, I want "Status" field equal to "Moved".

Please guide me on this. Thanks for help.