Tutorial by Examples: l

The term 'heap' is a general computing term meaning an area of memory from which portions can be allocated and deallocated independently of the memory provided by the stack. In C++ the Standard refers to this area as the Free Store which is considered a more accurate term. Areas of memory allocate...

There are situations when we don't want to rely upon Free Store for allocating memory and we want to use custom memory allocations using new. For these situations we can use Placement New, where we can tell `new' operator to allocate memory from a pre-allocated memory location For example int a4b...

A std::string containing a number can be converted into an integer type, or a floating point type, using conversion functions. Note that all of these functions stop parsing the input string as soon as they encounter a non-numeric character, so "123abc" will be converted into 123. The s...

The fundamental concept of the customizer is that admins can live preview changes to their site, and then permanently add them. The following can be copied and pasted into a theme's functions.php file to Add a customizer section called My First Section Add a customizer setting called Hello Worl...

Instantiating a socket can be done in various ways. by 2 line declaration & instantiation: First we need to define a variable which will hold a Socket class object: Socket socket; then we can create a Socket class object: socket = new Socket(); We can also make a one line defin...

Alternate return is a facility to control the flow of execution on return from a subroutine. It is often used as a form of error handling: real x call sub(x, 1, *100, *200) print*, "Success:", x stop 100 print*, "Negative input value" stop 200 print*, "Input va...

Installing aws cli in Ubuntu / Debian Instance sudo apt-get install -y python-dev python-pip sudo pip install awscli aws --version aws configure Installing aws cli using python Using pip you can install aws cli in windows, OS X and Linux sudo pip install awscli Configuring the AWS Comman...

Unit Test Unit tests are used to ensure that your code has no syntax error and to test the logic of your code to work as what you expected. Quick example: src/AppBundle/Calculator/BillCalculator.php <?php namespace AppBundle\Calculator; use AppBundle\Calculator\TaxCalculator; class Bi...

A subprogram (which defines a procedure), can be either a subroutine or a function; it is said to be an internal subprogram if it is called or invoked from the same program or subprogram that contains it, as follows program my_program ! declarations ! executable statements, ! among which...

A subprogram is said to be external when it is not contained in the main program, nor in a module or antoher subprogram. In particular it can be defined by means of a programming language other than Fortran. When an external subprogram is invoked, the compiler cannot access to its code, so all the ...

Controlled form components are defined with a value property. The value of controlled inputs is managed by React, user inputs will not have any direct influence on the rendered input. Instead, a change to the value property needs to reflect this change. class Form extends React.Component { con...

Uncontrolled components are inputs that do not have a value property. In opposite to controlled components, it is the application's responsibility to keep the component state and the input value in sync. class Form extends React.Component { constructor(props) { super(props); th...

JSTL is part of the Java EE API and included in Java EE application servers such as WildFly, TomEE, GlassFish, but not in barebones servletcontainers such as Tomcat and Jetty. JSTL are the taglibs which you import from http://java.sun.com/jsp/jstl/* namespace. JSTL must not be confused with a "...

Use the continuation character (ellipsis) ... to continue long statement. Example: MyFunc( parameter1,parameter2,parameter3,parameter4, parameter5, parameter6,parameter7, parameter8, parameter9) can be replaced by: MyFunc( parameter1, ... parameter2, ... parameter3, ... ...

Floating-point numbers cannot represent all real numbers. This is known as floating point inaccuracy. There are infinitely many floating points numbers and they can be infinitely long (e.g. π), thus being able to represent them perfectly would require infinitely amount of memory. Seeing this was a ...

Objective-C NSString *textToShare = @"StackOverflow Documentation!! Together, we can do for Documentation what we did for Q&A."; NSURL *documentationURL = [NSURL URLWithString:@"http://stackoverflow.com/tour/documentation"]; NSArray *objectsToShare = @[textToShare, docum...

Steps to create Hello Spring: Investigate Spring Boot to see if that would better suit your needs. Have a project set up with the correct dependencies. It is recommended that you are using Maven or Gradle. create a POJO class, e.g. Employee.java create a XML file where you can define your clas...

string str = "this--is--a--complete--sentence"; string[] tokens = str.Split(new[] { "--" }, StringSplitOptions.None); Result: [ "this", "is", "a", "complete", "sentence" ]

It is also possible to use Scala's string interpolation feature to create elaborate extractors (pattern matchers), as perhaps most famously employed in the quasiquotes API of Scala macros. Given that n"p0${i0}p1" desugars to new StringContext("p0", "p1").n(i0), it is p...

To the average R user, the list structure may appear to be the one of the more complicated data structures to manipulate. There are no guarantees that all the elements within it are of the same type; There is no guaranteed structure of how complicated/non-complicated that the list would be (An eleme...