Tutorial by Examples: g

A pointer (resp. reference) to an object type can be converted to a pointer (resp. reference) to any other object type using reinterpret_cast. This does not call any constructors or conversion functions. int x = 42; char* p = static_cast<char*>(&x); // error: static_cast cannot perf...

Default behavior when cloning an object is to perform a shallow copy of the object's fields. In that case, both the original object and the cloned object, hold references to the same objects. This example shows that behavior. import java.util.List; public class Sheep implements Cloneable { ...

To copy nested objects, a deep copy must be performed, as shown in this example. import java.util.ArrayList; import java.util.List; public class Sheep implements Cloneable { private String name; private int weight; private List<Sheep> children; public Sheep(Str...

Exceptions represent programmer-level bugs like trying to access an array element that doesn’t exist. Errors are user-level issues like trying load a file that doesn’t exist. Because errors are expected during the normal execution of a program. Example: NSArray *inventory = @[@"Sam"...

Before we download and install Composer, we need to make sure our server has all dependencies installed. First, update the package manager cache by running: sudo apt-get update Now, let's install the dependencies. We'll need curl in order to download Composer and php5-cli for installing and run...

Here we will simply use the installer. This is the easiest way to get Composer set up on your machine. Download and run Composer-Setup.exe. It will install the latest composer version and set up your PATH so that you can just call composer from any directory in your command line. Note: Close your...

If a bean is defined with singleton scope, there will only be one single object instance initialized in the Spring container. All requests to this bean will return the same shared instance. This is the default scope when defining a bean. Given the following MyBean class: public class MyBean { ...

First make utility class or use this method in class needed public class UIUtils { public static BitmapImageViewTarget getRoundedImageTarget(@NonNull final Context context, @NonNull final ImageView imageView, final float radius) { retur...

The following examples will use this class hierarchy: struct A { int m; }; struct B : A {}; struct C : B {}; The conversion from derived class type to base class type is preferred to user-defined conversions. This applies when passing by value or by reference, as well as when converting pointe...

echo %var% This code will echo the value of var If setLocal EnableDelayedExpansion is used, the following will echo the value of var (the standard expression %var% will not work in that context). echo !var! In batch files, variables can be used in any context, including as parts of commands ...

Warning: The functions atoi, atol, atoll and atof are inherently unsafe, because: If the value of the result cannot be represented, the behavior is undefined. (7.20.1p1) #include <stdio.h> #include <stdlib.h> int main(int argc, char** argv) { int val; if (argc < 2) ...

Before we start... In terms of application layers your ViewModel is a class containing all the business logic and rules making the app do what it should according to the requirements. It's also important to make it as much independent as possible reducing references to UI, data layer, native featur...

Assignment arguments appear at the end of an awk invocation, in the same area as file variables, both -v assignments and argument assignments must match the following regular expression. (assuming a POSIX locale) ^[[:alpha:]_][[:alnum:]_]*= The following example assumes a file file containing th...

$ jekyll build # The current site folder will be built into the ./_site directory $ jekyll build --destination /var/www/ # The current site folder will be generated into /var/www/ $ jekyll build --watch # The current site folder will be built into the ./_site directory and will be kept up t...

map Overview A key sequence can be re-mapped to another key sequence using one of the map variants. As an example, the following typical map will exit Insert mode when you press jk in quick sequence: :inoremap jk <Esc> map Operator There are multiple variants of :map for different modes...

This will trigger the native email client for sharing text. Parameters : Email To address, Subject, Body. Code Sample : you can call the function wherever you need, (mostly inside click listeners) like below Calling function shareEmail("[email protected]", "Email sharing example&q...

Use a HashMap to store the parameters that should be sent to the server through POST parameters: HashMap<String, String> params; Once the params HashMap is populated, create the StringBuilder that will be used to send them to the server: StringBuilder sbParams = new StringBuilder(); ...

Although available, defining a class from scratch is not recommended in modern Perl. Use one of helper OO systems which provide more features and convenience. Among these systems are: Moose - inspired by Perl 6 OO design Class::Accessor - a lightweight alternative to Moose Class::Tiny...

In this example we create a goroutine (a function running in a separate thread) that accepts a chan parameter, and simply loops, sending information into the channel each time. In the main we have a for loop and a select. The select will block processing until one of the case statements becomes tru...

So here, I have removed the for loops, and made a timeout by adding a second case to the select that returns after 3 seconds. Because the select just waits until ANY case is true, the second case fires, and then our script ends, and chatter() never even gets a chance to finish. // Use of the select...