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Articles on Trending Technologies
Technical articles with clear explanations and examples
What happens if we overload default methods of an interface in java?
An interface in Java is similar to a class but, it contains only abstract methods and fields which are final and static.Since Java8 static methods and default methods are introduced in interfaces.Default methods − Unlike other abstract methods these are the methods that can have a default implementation. If you have a default method in an interface, it is not mandatory to override (provide body) it in the classes that are already implementing this interface.In short, you can access the default methods of an interface using the objects of the implementing classes.Exampleinterface MyInterface{ public static int num = 100; ...
Read MoreCan we overload methods of an interface in Java?
Polymorphism is the ability of an object to perform different actions (or, exhibit different behaviors) based on the context.Overloading is one of the mechanisms to achieve polymorphism where a class contains two methods with the same name and different parameters.Whenever you call this method the method body will be bound with the method call based on the parameters.ExampleIn the following Java program, the Calculator class has two methods with name addition the only difference is that one contains 3 parameters and the other contains 2 parameters.Here, we can call the addition method by passing two integers or three integers. Based ...
Read MoreHow to override only few methods of interface in Java?
Once you implement an interface from a concrete class you need to provide implementation to all its methods. If you try to skip implementing methods of an interface at compile time an error would be generated.Exampleinterface MyInterface{ public void sample(); public void display(); } public class InterfaceExample implements MyInterface{ public void sample(){ System.out.println("Implementation of the sample method"); } public static void main(String args[]) { InterfaceExample obj = new InterfaceExample(); obj.sample(); } }Compile-time errorInterfaceExample.java:5: error: InterfaceExample is not abstract and does not override abstract method display() ...
Read MoreIs parent child hierarchy important on throws while overriding in Java?
When you try to handle an exception (checked) thrown by a particular method, you need to catch it using the Exception class or super class of the Exception occurred.In the same way while overriding the method of a super class, if it throws an exception −The method in the sub-class should throw the same exception or its sub type.The method in the sub-class should not throw its super type.You can override it without throwing any exception.When you have three classes named Demo, SuperTest and, Super in (hierarchical) inheritance, if Demo and SuperTest have a method named sample().Exampleclass Demo { ...
Read MoreMaximum length subarray with LCM equal to product in C++
Suppose we have an array A. We have to find the maximum length of the subarray, whose LCM is the same as the product of the elements of that subarray. If that kind of subarray is not found, then return -1. Suppose array is {6, 10, 21}, then the length is 2, as the subarray {10, 21} is there, whose LCM is 210, and the product is also 210.The approach is straight forward. We have to check every possible subarray of length greater or equals to 2. If the subarray is satisfying the condition, then update the answer as a ...
Read MoreWhen overriding clone method, why do we need to declare it as public in Java?
The clone() method belongs to the class named Object of the java.lang package, it accepts an object as a parameter creates and returns a copy of it.In order to use this method, you need to make sure that your class implements the Cloneable (marker) interface.Examplepublic class CloneExample implements Cloneable { private String name; private int age; public CloneExample(String name, int age){ this.name = name; this.age = age; } public void displayData(){ System.out.println("Name : "+this.name); System.out.println("Age : "+this.age); } public static void ...
Read MoreDifference between notify() and notifyAll() in Java
Both notify and notifyAll are the methods of thread class and used to provide notification for the thread.But there are some significant differences between both of these methods which we would discuss below.Following are the important differences between notify and notifyAll.Sr. No.KeynotifynotifyAll1NotificationIn case of multiThreading notify() method sends the notification to only one thread among the multiple waiting threads which are waiting for lock.While notifyAll() methods in the same context sends the notification to all waiting threads instead of single one thread.2Thread identificationAs in case of notify the notification is sent to single thread among the multiple waiting threads so ...
Read MoreMaximum positive integer divisible by C and is in the range [A, B] in C++
Here we will see one interesting problem. let us consider we have three integers A, B, and C. We have to find one minimum integer X, such that X mod C = 0, and X is not in the range [A, B]. If the values of A, B and C are 5, 10 and 4 respectively, then the value of X will be 4. We have to follow these steps to get the solution −Steps −If C is not in the range [A, B], then return C as a resultOtherwise get the first multiple of C, which is greater than ...
Read MoreC++ program to concatenate a string given number of times?
Here we will see how we can concatenate a string n number of times. The value of n is given by the user. This problem is very simple. In C++ we can use + operator for concatenation. Please go through the code to get the idea.AlgorithmconcatStrNTimes(str, n)begin res := empty string for i in range 1 to n, do res := concatenate res and res done return res endExample#include using namespace std; main() { string myStr, res = ""; int n; cout > myStr; cout > n; for(int i= 0; i < n; i++) { res += myStr; } cout
Read MoreC++ Program to count Vowels in a string using Pointer?
To get the vowels from a string, we have to iterate through each character of the string. Here we have to use pointers to move through the string. For this we need C style strings. If the string is pointed by str, then *str will hold the first character at the beginning. Then if str is increased, the *str will point next character and so on. If the character is in [a, e, i, o, u] or [A, E, I, O, U] then it is vowel. So we will increase the countAlgorithmcountVowels(str)begin count := 0 for each character ...
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