Why should we use new , instead of virtual

Question

Can anyone explain why should we use new Or when to use new and when to use virtual , any real life example

Menaka Devi · Answer

Hi, When to use new - if you want to hide something in the base class method. When to use virtual - if you want to override something in the base class method. Real Life Example : class Nokia { public virtual void BatteryCapacity() { console.writeline("Capacity : 3000mAh"); } public void MobileBootSound() { console.writeline("Nokia boot sound") } } class Samsung : Nokia { public override void BatteryCapacity() { console.writeline("Capacity : 4500mAh"); //here upgrading 3000 + 1500(so 3000 is included) } public new MobileBootSound() { console.writeline("Samsung boot sound"); //here tone is totally different } } class Moto : Nokia { public override void BatteryCapacity() { console.writeline("Capacity : 4000mAh"); //here upgrading 3000 + 1000(so 3000 is included) } public new MobileBootSound() { console.writeline("Moto boot sound"); //here also tone is totally different } } See three mobile companies A,B&C for ex battery capacity of A is 3000 mAh, B & C just used the same battery capacity of A and increased few mAh i.e. 3000 mAh + 1000 mAh (virtual-overriding) But B&C instead of copy or override the boot sound of the A mobile, they implemented the new boot sound(here new - overhiding the boot sound)

Ramesh Palanivel · Answer

Hi Nikil, Try this URL, It will help you!.. http://www.dotnettricks.com/learn/csharp/understanding-virtual-override-and-new-keyword-in-csharp

nikhil kapoor · Answer

https://stackoverflow.com/questions/9590243/when-to-use-new-instead-of-override-c-sharp

nikhil kapoor · Answer

Hi , That was really wonderful reply thank you so much , but sry being a noob i have another question In real world, work culture and environment of all companies are same but each companies ideas,techniques should hide from each other. virtual & override - For overriding the base class method in derived class, you have to declare base class method as virtual and derived class method as override why can't i use new in this ? i know new will create another copy except that any other reason ? i am baiscally clear with thier fundamental but the question is When to use new and when to use virtual , if u can explain with any requierment :)

Menaka Devi · Answer

Hi, new - For hiding the base class method from derived class simply declare the derived class method with new keyword. Class CompanyA { public void Techniques(){ Console.WriteLine("Company A - techniques & ideas"); } } Class CompanyB: CompanyA { public new void Techniques(){ Console.WriteLine("Company B - techniques & ideas"); } } In real world, work culture and environment of all companies are same but each companies ideas,techniques should hide from each other. virtual & override - For overriding the base class method in derived class, you have to declare base class method as virtual and derived class method as override Class CompanyA { public virtual void Designation(){ Console.WriteLine("Company A - employees designation"); } } Class CompanyB: CompanyA { public override void Designation(){ Console.WriteLine("Company B - employees designation"); } } In real world, in each companies the designation of employees may vary(i.e. software developer,system engineer but these people are doing the same work) for further please go through this link - http://www.dotnettricks.com/learn/csharp/understanding-virtual-override-and-new-keyword-in-csharp