Tutorial by Examples: re

2.1 Required keyword arguments were introduced in Ruby 2.1, as an improvement to keyword arguments. To define a keyword argument as required, simply declare the argument without a default value. def say(message:) puts message end say # => ArgumentError: missing keyword: message say ...

C++17 A storage class specifier that hints to the compiler that a variable will be heavily used. The word "register" is related to the fact that a compiler might choose to store such a variable in a CPU register so that it can be accessed in fewer clock cycles. It was deprecated starting ...

Returns control from a function to its caller. If return has an operand, the operand is converted to the function's return type, and the converted value is returned to the caller. int f() { return 42; } int x = f(); // x is 42 int g() { return 3.14; } int y = g(); // y is 3 If re...

Dependencies can be added for specific product flavors in a similar fashion as build configurations. android { ... productFlavors { flavor1 { //... } flavor2 { //... } } } dependencies { flavor1Compile 'com.and...

To remove an element from a map use the .delete() method. map.delete(key); Example: const map = new Map([[1, 2], [3, 4]]); console.log(map.get(3)); // 4 map.delete(3); console.log(map.get(3)); // undefined This method returns true if the element existed and has been removed, otherwise fal...

To enable resource shrinking, set the shrinkResources property to true in your build.gradle file. android { ... buildTypes { release { minifyEnabled true shrinkResources true proguardFiles getDefaultProguardFile('proguard-android.txt'), 'p...

All libraries come with resources that are not necessary useful to your application. For example Google Play Services comes with translations for languages your own application don’t even support. You can configure the build.gradle file to specify which resource you want to keep. For example: de...

Using requestAnimationFrame may on some systems update at more frames per second than the 60fps. 60fps is the default rate if the rendering can keep up. Some systems will run at 120fps maybe more. If you use the following method you should only use frame rates that are integer divisions of 60 so th...

R provides two additional looping constructs, while and repeat, which are typically used in situations where the number of iterations required is indeterminate. The while loop The general form of a while loop is as follows, while (condition) { ## do something ## in loop body } whe...

First, let's see three different ways of extracting data from a file. string fileText = File.ReadAllText(file); string[] fileLines = File.ReadAllLines(file); byte[] fileBytes = File.ReadAllBytes(file); On the first line, we read all the data in the file as a string. On the second line, we r...

This example is about replacing a List element while ensuring that the replacement element is at the same position as the element that is replaced. This can be done using these methods: set(int index, T type) int indexOf(T type) Consider an ArrayList containing the elements "Program sta...

A conversion that involves calling an explicit constructor or conversion function can't be done implicitly. We can request that the conversion be done explicitly using static_cast. The meaning is the same as that of a direct initialization, except that the result is a temporary. class C { std:...

This example shows how to render text along an arc. It includes how you can add functionality to the CanvasRenderingContext2D by extending its prototype. This examples is derived from the stackoverflow answer Circular Text. Example rendering Example code The example adds 3 new text renderi...

Generally execute() command is used for fire and forget calls (without need of analyzing the result) and submit() command is used for analyzing the result of Future object. We should be aware of key difference of Exception Handling mechanisms between these two commands. Exceptions from submit() ar...

C++14 C++14 introduced a standard way of deprecating functions via attributes. [[deprecated]] can be used to indicate that a function is deprecated. [[deprecated("reason")]] allows adding a specific reason which can be shown by the compiler. void function(std::unique_ptr<A> &&a...

Thread-local storage can be created using the thread_local keyword. A variable declared with the thread_local specifier is said to have thread storage duration. Each thread in a program has its own copy of each thread-local variable. A thread-local variable with function (local) scope will be in...

Cross-site request forgery, also known as one-click attack or session riding and abbreviated as CSRF or XSRF, is a type of malicious exploit of a website where unauthorized commands are transmitted from a user that the website trusts. Learn more To enable CSRF protection, add the CsrfViewMid...

Creates a path from a set of points [{x:?,y:?},{x:?,y:?},...,{x:?,y:?}] with rounded corners of radius. If the corner angle is too small to fit the radius or the distance between corners does not allow room the corners radius is reduced to a best fit. Usage Example var triangle = [ { x: 200...

Here is a very simple example to illustrate how to write a NIF. Directory structure: nif_test ├── c_src │   ├── Makefile │   └── nif_test.c ├── rebar.config └── src ├── nif_test.app.src └── nif_test.erl This structure can be easily initialized using Rebar3: $ rebar3 new lib nif_...

Comparator.comparing(Person::getName) This creates a comparator for the class Person that uses this person name as the comparison source. Also it is possible to use method version to compare long, int and double. For example: Comparator.comparingInt(Person::getAge) Reversed order To create ...