3 Ways To Foreclose Method Overriding Inwards Coffee - Private, Static Together With Final

Every Java programmer knows that final modifier tin give the sack hold upwardly used to forestall method overriding inwards Java because at that spot is no way someone tin give the sack override in conclusion methods; but, apart from final modifier, is at that spot whatsoever other way to prevent method overriding inwards Java? This was the exact question, asked to 1 of my friend inwards a recent Java interview at 1 of the leading Investment bank. I guess, he was lucky to acquire this inquiry because he already knows those tricks as well as was able to reply it quickly. When he told me nigh his experience,  I didn't sympathise why someone inquire this question? What is the purpose? What they were trying to detect out? I tin give the sack sympathise if they own got asked what's the best way to forestall method overriding inwards Java, or what is the remove chances of overriding? Anyway, It gives me an chance to recap about of the other technique (syntactically) to forestall a method from beingness overridden as well as write this weblog post service to percentage about mystery tricks from Java world. Some of you lot mightiness hold upwardly aware of those non obvious way to forestall method overriding, merely if you lot don't, hither is your chance to learn.

Private, Static as well as Final Methods - Can't Overridden inwards Java

Apart from in conclusion methods at that spot are 2 to a greater extent than techniques which you lot tin give the sack work to forestall a method from beingness overridden inwards Java. If you lot are familiar amongst private as well as static modifier inwards Java, therefore you lot may hold upwardly knowing that someone method is non accessible inwards subclass, which way they tin give the sack non hold upwardly overridden every bit well, because overriding happens at tike class. Similarly, static methods tin give the sack non hold upwardly overridden inwards Java, because they are resolved as well as bonded during compile time, spell overriding takes house at runtime. They are resolved based upon the type as well as non object. Overriding happens due to polymorphic belongings of objects. By the way, can you lot override static methods inwards Java and why a static method tin give the sack non hold upwardly overridden inwards Java, are every bit good 2 of the most oft asked Java questions. In short, apart from final modifier, you lot tin give the sack every bit good work static as well as private modifier to forestall a method from beingness overridden.

Best Way to Prevent Method Overriding inwards Java

As far every bit Java best practise is concern, you lot should ever work final keyword to dot that a method is non meant for overriding. in conclusion modifier has a readability advantage, every bit good every bit consistency advantage, because every bit before long every bit a Java programmer sees a in conclusion method, he knows that this tin give the sack non hold upwardly overridden. Private method implies that this method is alone accessible inwards this class, which inwards turns implies that, you tin give the sack non override someone methods on derived class. As you lot tin give the sack see, someone methods nonetheless requires 1 to a greater extent than measurement to realize that it tin give the sack non hold upwardly overridden. What creates confusion amongst private as well as static methods are that, you lot tin give the sack shroud these methods inwards subclass. There is a divergence betwixt method hiding as well as method overriding, Influenza A virus subtype H5N1 method is hidden inwards subclass, if it signature is same every bit of super bird method, merely at a telephone phone to hidden method is resolved during compile time, spell a telephone phone to overridden method is resolved during run time.

In damage of performance, I retrieve all 3 private, static as well as final method performs to a greater extent than or less same, because they all bonded during compile fourth dimension using static binding. Another argue of using final modifier to forestall method overriding is compile fourth dimension check. Since an travail to override a in conclusion method is a compilation fault inwards Java, it prevents accidental overriding. On the other mitt private as well as static methods tin give the sack unknowingly shroud super bird method as well as do subtle bugs, because compiler volition non flag whatsoever fault or warning. By the way, you lot tin give the sack avoid this sort of accidental method overriding past times using @Override annotation inwards Java. If you lot work @Override annotation, whenever you lot intent to override a method, compiler volition flag fault as well as salve you lot from accidentally hiding private as well as static methods. Just seek next Java computer programme later on putting @Override notation on static as well as someone method, to run across how compiler helps you.

Code Example - Private, Static as well as Final method

In this Java program, nosotros volition do 2 classes Base as well as Derived amongst 3 methods, 1 static, 1 in conclusion as well as 1 private. By observing output, you lot tin give the sack run across verify that final, someone as well as static methods tin give the sack non hold upwardly overridden inwards Java. Since overriding in conclusion methods is compilation error, I had to comment that code. You tin give the sack clearly run across that, fifty-fifty though nosotros own got similar private as well as static method inwards Derived class, as well as nosotros are using Derived object to telephone phone those method, they are non called. Which way private as well as static method tin give the sack alone hold upwardly hidden, merely non overridden.

package test;  /**   * Java computer programme to demo that private, static as well as in conclusion method tin give the sack non hold upwardly   * overridden inwards Java.   *   * @author Javin Paul   */ public class PrivateFinalStaticOverridingTest {       public static void main(String args[]) {           // Reference variable of type Base - Object of type Derived         Base b = new Derived();               System.out.println(b.version());         System.out.println(b.name());                 }       }  /**   * Base Class which contains 3 methods amongst final, static, as well as someone   * modifier, to demo that these method can't hold upwardly overridden inwards Java.   *   * @author Javin   */ class Base{       public final String version(){         where(); // This volition telephone phone Base bird where() method         return "1.0.0";     }       public static String name(){         return "Base";     }       private void where(){         System.out.println("Inside Base Class");     } }  /**   * Derived Class, which extends Base as well as tries to override final, static   * as well as someone methods inwards Java.    * @author Javin   */ class Derived extends Base{       // Compilation Error : Final method can't hold upwardly overridden inwards Java //    world in conclusion String version(){ //        provide "2.0.0"; //    }       // Hidden static method - Same Signature merely bonded at compile time     public static String name(){         return "Derived";     }       // Hidden someone method - Same signature merely resolved at compile time     private void where(){         System.out.println("Inside Derived Class");     } }  Output: Inside Base Class 1.0.0 Base

In the code above, you lot tin give the sack run across that inwards Base.java nosotros own got 3 methods, in conclusion method version(), static method name() as well as someone method where(). In the sub bird Derived.java, nosotros tried to override final method merely compiler gave us error, forcing us to comment that code. Though nosotros are able to do someone as well as static method of same cite as well as syntax inwards the sub class, merely this is non overriding. To verify that nosotros ran the computer programme as well as computer programme called methods of derived object amongst type of base of operations class. In this illustration whatsoever overridden method volition hold upwardly execute code defined inwards derive bird merely you lot tin give the sack run across from output that code defined inwards Base bird is executed. In short, its non possible to override someone as well as static method inwards Java.


That's all nigh 3 ways to forestall a method from beingness overridden inwards Java. Remember, though syntactically you lot tin give the sack work private, static as well as final modifier to forestall method overriding, merely you should ever work in conclusion modifier to forestall overriding. in conclusion is best way to say a method is consummate as well as can't hold upwardly overridden. It's every bit good a practiced coding practise inwards Java to work @Override annotation, when your intention is overriding as well as non hiding, this volition forestall subtle bugs. You should every bit good hold upwardly clear, when to work in conclusion keyword inwards Java, because it limits client's powerfulness to override something, merely same fourth dimension necessary to forestall safety as well as sensitive deportment intact.

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