Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Programming Articles
Page 1510 of 2547
What are the differences between a static block and a constructor in Java?
Static blockThe static blocks are executed at the time of class loading.The static blocks are executed before running the main () method.The static blocks don't have any name in its prototype.If we want any logic that needs to be executed at the time of class loading that logic needs to placed inside the static block so that it will be executed at the time of class loading.Syntaxstatic { //some statements }Examplepublic class StaticBlockTest { static { System.out.println("Static Block!"); } public static void main(String args[]) { System.out.println("Welcome to Tutorials Point!"); } }OutputStatic Block! Welcome ...
Read MoreIntStream findFirst() method in Java
The findFirst() method in Java returns an OptionalInt describing the first element of this stream. If the stream is empty, an empty OptionalInt is returned.The syntax is as followsOptionalInt findFirst()Here, OptionalInt is a container object which may or may not contain an int value.To work with the IntStream class in Java, import the following packageimport java.util.stream.IntStream;For OptionalInt class, import the following packageimport java.util.OptionalInt;First, create an IntStream and add elementsIntStream intStream = IntStream.of(30, 45, 70, 80, 90, 120);Now, get the first element of this streamOptionalInt res = intStream.findFirst();The following is an example to implement IntStream findFirst() method in JavaExampleimport java.util.OptionalInt; import ...
Read MoreLongStream forEachOrdered() method in Java
The forEachOrdered() method in Java performs an action for each element of this stream, guaranteeing that each element is processed in encounter order for streams that have a defined encounter order.The syntax is as follows −void forEachOrdered(LongConsumer action)Here, parameter wrapper is a non-interfering action to perform on the elements. LongConsumer represents an operation that accepts a single long-valued argument and returns no result.To use the LongStream class in Java, import the following package −import java.util.stream.LongStream;The following is an example to implement LongStream forEachOrdered() method in Java −Exampleimport java.util.*; import java.util.stream.LongStream; public class Demo { public static void main(String[] ...
Read MorePointers, smart pointers and shared pointers in C++
PointersPointers are used to store the address of variable.SyntaxType *pointer;InitializationType *pointer; Pointer = variable name;Functionspointers are used to store address of variable.pointers can have a null value assigned.pointer can be referenced by pass by reference.a pointer has its own memory address and size on the stack.Example#include using namespace std; int main() { // A normal integer variable int a = 7; // A pointer variable that holds address of a. int *p = &a; // Value stored is value of variable "a" cout
Read MoreWhat are copy constructors in Java?
Generally, the copy constructor is a constructor which creates an object by initializing it with an object of the same class, which has been created previously.Java supports for copy constructors but unlike C language, Java does not provide an explicit copy constructor you need to define it yourself.writing a copy constructorUsually, to initialize the values of instance variables of a class (one way) we create a parameterized constructor accepting the values for all instance variables and initialize them with the given values.int name; int age; public Student(String name, int age){ this.name = name; this.age ...
Read MoreRAII and smart pointers in C++
RAII in C++RAII (Resource Acquisition Is Initialization) is C++ technique which control the life cycle of resource. It is a class variant and is tied to object life time.It encapsulates several resources into class where resource allocation is done by constructor during object creation and resource deallocation is done by destructor during object destruction.Resource is guaranteed to be held till the object is alive.Examplevoid file_write { Static mutex m; //mutex to protect file access lock_guard lock(m); //lock mutex before accessing file ofstream file("a.txt"); if (!file.is_open()) //if file is not open throw runtime_error("unable to open file"); ...
Read MoreIntStream.Builder build() method in Java
The build() method builds the stream. It transitions the builder to the built state. It returns the built stream. First, add elements to the streamIntStream.Builder builder = IntStream.builder(); builder.add(10); builder.add(25); builder.add(33);Now the stream is in the built phasebuilder.build().forEach(System.out::println);The syntax is as followsIntStream build()The following is an example to implement IntStream.Builder build() method in JavaExampleimport java.util.stream.IntStream; public class Demo { public static void main(String[] args) { IntStream.Builder builder = IntStream.builder(); System.out.println("Elements in the stream..."); builder.add(10); builder.add(25); builder.add(33); builder.add(42); builder.add(55); ...
Read MoreFinding all words that start with an 'a' in Java
All the words that start with a can be found in a string by using regular expressions in Java. The regular expressions are character sequences that can be used to match other strings using a specific pattern syntax. The regular expressions are available in the java.util.regex package which has many classes but the most important are Pattern class and Matcher class.A program that finds all words that start with an 'a' is using regular expressions is given as follows:Exampleimport java.util.regex.Matcher; import java.util.regex.Pattern; public class Demo { public static void main(String args[]) throws Exception { String str ...
Read MoreSecureRandom nextBytes() method in Java
The number of random bytes as specified by the user can be obtained using the nextBytes() method in the class java.security.SecureRandom. This method requires a single parameter i.e. a random byte array and it returns the random bytes as specified by the user.A program that demonstrates this is given as follows −Exampleimport java.security.*; import java.util.*; public class Demo { public static void main(String[] argv) { try { SecureRandom sRandom = SecureRandom.getInstance("SHA1PRNG"); String s = "Apple"; byte[] arrB = s.getBytes(); System.out.println("The ...
Read MoreSet vs Map in C++ STL
Set is an abstract data type in which each element has to be unique because the value of the element identifies it. The value of the element cannot be modified once it is added to the set, but it is possible to remove and add the modified value of that element.A Map is an associative container that store elements in a mapped fashion. Each element has a key value and a mapped value. No two mapped values can have the same key values.So, it is clear from above that, set contains the only key, and map contains a value with ...
Read More