Tutorial by Examples: re

The response to a CORS request must include an Access-Control-Allow-Origin header, which dictates what origins are allowed to use the CORS resource. This header can take one of three values: An origin. Doing this permits requests from that origin only. The character *. This permits requests from...

Allowing user credentials or the user's session to be sent with a CORS request allows the server to persist user data across CORS requests. This is useful if the server needs to check if the user is logged in before providing data (for example, only performing an action if a user is logged in - this...

A basic CORS request is allowed to use one of only two methods: GET POST and only a few select headers. POST CORS requests can additionally choose from only three content types. To avoid this issue, requests that wish to use other methods, headers, or content types must first issue a preflig...

When a server receives a preflight request, it must check if it supports the requested method and headers, and send back a response that indicates its ability to support the request, as well as any other permitted data (such as credentials). These are indicated in access-control Allow headers. The ...

A Regexp can be created in three different ways in Ruby. using slashes: / / using %r{} using Regex.new #The following forms are equivalent regexp_slash = /hello/ regexp_bracket = %r{hello} regexp_new = Regexp.new('hello') string_to_match = "hello world!" #All of th...

When we want to count the number of items in an iterable, that meet some condition, we can use comprehension to produce an idiomatic syntax: # Count the numbers in `range(1000)` that are even and contain the digit `9`: print (sum( 1 for x in range(1000) if x % 2 == 0 and '9' in str...

Like any other java program, every swing program starts with a main method. The main method is initiated by the main thread. However, Swing components need to be created and updated on the event dispatch thread (or short: EDT). To illustrate the dynamic between the main thread and the EDT take a loo...

defmodule Processes do def receiver do receive do {:ok, val} -> IO.puts "Received Value: #{val}" _ -> IO.puts "Received something else" end end end iex(1)> pid = spawn(Processes, ...

Recursion can be used to receive multiple messages defmodule Processes do def receiver do receive do {:ok, val} -> IO.puts "Received Value: #{val}" _ -> IO.puts "Received something else" end...

For a function or subroutine to be useful it has to be referenced. A subroutine is referenced in a call statement call sub(...) and a function within an expression. Unlike in many other languages, an expression does not form a complete statement, so a function reference is often seen in an ass...

You create new ScriptableObject instances through ScriptableObject.CreateInstance<T>() T obj = ScriptableObject.CreateInstance<T>(); Where T extends ScriptableObject. Do not create ScriptableObjects by calling their constructors, ie. new ScriptableObject(). Creating ScriptableO...

Extra care should be taken when accessing serialized fields in a ScriptableObject instance. If a field is marked public or serialized through SerializeField, changing its value is permanent. They do not reset when exiting playmode like MonoBehaviours do. This can be useful at times, but it can also...

preg_match can be used to parse string using regular expression. The parts of expression enclosed in parenthesis are called subpatterns and with them you can pick individual parts of the string. $str = "<a href=\"http://example.org\">My Link</a>"; $pattern = "/...

Often you will get into a state where you have a partially typed command sequence in progress, but you want to abort it. You can abort it with either of the following keybindings: C-g EscEscEsc

Hash references are scalars which contain a pointer to the memory location containing the data of a hash. Because the scalar points directly to the hash itself, when it is passed to a subroutine, changes made to the hash are not local to the subroutine as with a regular hash, but instead are global...

If profiling your build shows significant time spend in Configuring Projects, the Configure on Demand option might improve your performance. You can enable Configure on Demand mode by editing $GRADLE_USER_HOME/.gradle/gradle.properties (~/.gradle/gradle.properties by default), and setting org.gradl...

1.6.5 git clone <url> --recursive Clones the repository and also clones all submodules. If the submodules themselves contain additional submodules, Git will also clone those.

A class or struct can also contain another class/struct definition inside itself, which is called a "nested class"; in this situation, the containing class is referred to as the "enclosing class". The nested class definition is considered to be a member of the enclosing class, b...

Const appName As String = "The App For That"

Dim surname As String 'surname can accept strings of variable length surname = "Smith" surname = "Johnson"