Programming Articles - Page 2439 of 3366

Date is number day, month and year. There are various ways to display a date.Here, we have a program to sort dates using selection sort. So let's learn about things that are used in this concept.Sorting datesThe concept of sorting dates needs a clear and well-versed knowledge of dates and their validations. Before we try sorting technique we need to check if the date inputted by the user is a valid date of not like 29-2 is only valid for leap years.After validation of dates comes the sorting of dates. For sorting, we will go in reverse order sorting years ... Read More

A subsequence is a sequence with the same order of the set of elements. For the sequence “stuv”, the subsequences are “stu”, “tuv”, “suv”, .... etc.For a string of length n, there can be 2n ways to create subsequence from the string.ExampleThe longest common subsequence for the strings “ ABCDGH ” and “ AEDFHR ” is of length 3. Live Demo#include #include using namespace std; int max(int a, int b); int lcs(char* X, char* Y, int m, int n){    if (m == 0 || n == 0)       return 0;    if (X[m - 1] == ... Read More

Hashing is the method by which we can map any length data element to a fixed size key. hashing works as key-value pairs.Hashing function is the function that does the mapping in a hash map. the data elements that are given as input to the Hash Function may get same hash key. In this case the elements may overlap. To avoid overlapping of elements which have the same hash key the concept of chaining was introduced.Creating a hashmapIn order to create a hashmap we need hashing function that will define the index value of the data element.We have a hash ... Read More

No there is not a standard function to check for null, undefined or blank values in JavaScript. However, there is the concept of truthy and falsy values in JavaScript. Values that coerce to true in conditional statements are called truth values. Those that resolve to false are called falsy. According to ES specification, the following values will evaluate to false in a conditional context − null undefined NaN empty string ("") 0 false This means that none of the following if statements will get executed − if (null) if (undefined) if ... Read More

Mathematical calculations can be done in C++ programming language using the mathematical functions which are included in math or cmath library. These mathematical functions are defined to do complex mathematical calculations. Let’s learn each of them one by one −sineThe sin method is used to calculate the sin of the angle given as an argument in degrees. This function accepts one double integer as an argument and returns a double integer which is the value of sin(x°).double sin(double)Calling syntaxdouble x = sin(23.4);Example Live Demo#include #include using namespace std; int main(){    double x = 45.3;    cout

A map is a data structure that stores information in the form of key and value pairs. In C++, map is defined in STL (standard template library) and store keys in an ordered form.Syntax to define a map −map map_name;The data type of any of these two data of the map can be any of the data types. We can have any of the primary data types or derived data types as key or value data types in a map.We can use any of the data types as the data type of the key of the map. Even a user-defined ... Read More

What is a virtual function?A virtual function is a method that does not have a definition when defined in the base class. This method is left black in the parent class and it is redefined in the child class.What is an abstract class?An abstract class is a class that has abstract members or at least one pure virtual function in its definition. An abstract class can never be instanced (creating an object). It can only be inherited and the methods could be overwritten.Can there be any virtual Destructors?Yes, These are legal in C++, but these are destructors are for base ... Read More

In multithreading when we deal with threads there comes the requirement of pause and start a thread for this Threading provides two methods wait and join which are used for the same.The following are the important differences between wait() and join().Sr. No.Keywait()join()1Declarationwait() method is defined in Object class and hence the wait() method is declared in java.lang package.join() method, on the other hand, is also defined in java.lang package but in Thread class.2Usagewait() method is primarily used for the inter-thread communication.On the other hand join() is used for adding sequencing between multiple threads, one thread starts execution after first thread ... Read More

HashSet and ArrayList both are one of the most important classes of the Java Collection framework.The following are the important differences between TreeMap, HashMap and LinkedHashMap.Sr. No.KeyTreeMapHashMapLinkedHashMap1Ordering of elementsThe elements inserted in TreeMap are sorted according to the natural ordering of its keys, or by a Comparator provided at map creation time, depending on which constructor is used.In case of HashMap it does not guarantees as to the order of the map also it does not guarantee that the order will remain constant over time.LinkedHashMap follows the insertion order of elements and also maintaining an order of elements inserted into ... Read More

HashMap and HashTable both are one of the most important classes of Java Collection framework. Both HashMap and HashTable stores the data in key value pair and at the time storing data hashing is used to hash the key and the resulting hash code is used as the index at which the value is stored within the table. But still, there are many differences between both these classes which we would discuss below.The following are the important differences between HashMap and HashTable.Sr. No.KeyHashMapHashTable1IntroductionHashmap is the advanced version of HashTable and is introduced as a new class in JDK 1.2.HashTable on ... Read More