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The java.lang.Math class contains methods for performing basic numeric operations such as the elementary exponential, logarithm, square root, and trigonometric functions. Class Declaration Following is the declaration for java.lang.Math class − public final class Math extends Object Field Following are the fields for java.lang.Math class − static double E − This is the double value that is closer than any other to e, the base of the natural logarithms. static double PI − This is the double value that is closer than any other to pi, the ratio of the circumference of a circle ... Read More
To deal with classes effectively, use the concept of covariance and contra variance. Let us consider the following as our class. One is a base class for class Two, whereas Two is a base class for Three. class One { } class Two: One { } class Three : Two { } A base class can hold a derived class, but the opposite is not possible. With Covariance, you can pass a derived type where a base type is expected. Co-variance can be used on array, interface, delegates, etc in C#. Contra variance is for parameters. ... Read More
The .NET Framework 4 brought the System.Collections.Concurrent namespace. This has several collection classes that are thread-safe and scalable. These collections are called concurrent collections because they can be accessed by multiple threads at a time. The following concurrent collection types use lightweight synchronization mechanisms: SpinLock, SpinWait, etc. These are new in .NET Framework 4. Let us see the concurrent collection in C# − Type Description BlockingCollection Bounding and blocking functionality for any type. ConcurrentDictionary Thread-safe implementation of a dictionary of key-value pairs. ConcurrentQueue Thread-safe implementation of a FIFO (first-in, first-out) queue. ConcurrentStack Thread-safe ... Read More
In this post we will try to print an array or matrix of numbers at console in same manner as we generally write on paper. For this the logic is to access each element of array one by one and make them print separated by a space and when row get to emd in matrix then we will also change the row Example Live Demo public class Print2DArray { public static void main(String[] args) { final int[][] matrix = { ... Read More
The java.util.PriorityQueue class is an unbounded priority queue based on a priority heap.Following are the important points about PriorityQueue − The elements of the priority queue are ordered according to their natural ordering, or by a Comparator provided at queue construction time, depending on which constructor is used. A priority queue does not permit null elements. A priority queue relying on natural ordering also does not permit insertion of non-comparable objects. Class declaration Following is the declaration for java.util.PriorityQueue class − public class PriorityQueue extends AbstractQueue implements Serializable Parameters Following ... Read More
For compiling unsafe code, you have to specify the /unsafe command-line switch with command-line compiler. For example, to compile a program named one.cs containing unsafe code, from command line, give the command − csc /unsafe one.cs Under Visual Studio IDE, enable use of unsafe code in the project properties. The following are the steps − Open Project properties by double clicking the properties node in the Solution Explorer. Click on the “Build” tab. Select the option "Allow unsafe code".
In python the str object, handles the text or string type data. Strings are immutable. The strings are sequence of Unicode characters. We can use single quote, double quotes or triple quotes to define the string literals. ‘This is a string with single quote’ “Another Text with double quotes” ‘’’Text using three single quotes’’’ or “””Text using three double quotes””” We can use triple quotes to assign multiline strings in python. There is different string related functions. Some of the String methods are as follows − Sr.No. Operation/Functions & Description 1 s.capitalize() Convert first ... Read More
As we know the primary role of the constructor is to instantiate a class object now if we made the constructor as private then we restrict its calling to be only in defining a class and not in some other class. Now the singleton class in Java is defined as the class which restricts the instantiation of a class and ensure that only one instance of the class exists in the JVM. After first time if instantiate the singleton class the new variable also points to the first instance created. In order to create a singleton class we could use ... Read More
The byte and bytearrays are used to manipulate binary data in python. These bytes and bytearrys are supported by buffer protocol, named memoryview. The memoryview can access the memory of other binary object without copying the actual data. The byte literals can be formed by these options. b‘This is bytea with single quote’ b“Another set of bytes with double quotes” b‘’’Bytes using three single quotes’’’ or b“””Bytes using three double quotes””” Some of the methods related to byte and bytearrays are − Method fromhex(string) The fromhex() method returns byte object. It takes a string where each byte is ... Read More
The sets are basically an unordered collection of distinct hash-table objects. We can use the set for some mathematical operations like set union, intersection, difference etc. We can also use set to remove duplicates from a collection. The set do not record the element position. It does not support the indexing, slicing or other sequence related operations. In python there are basically two types of sets. The set and the frozenset. The set type is mutable, whether the frozenset is immutable. We can perform add(), remove() and these kind of operations on set, but it is not possible for frozenset. ... Read More