Tutorial by Examples: re

An option item of a tree. This is an element within a tree that may be expanded or collapsed if it contains a sub-level group of treeitems. <ul role="tree"> <li role="treeitem"> Part 1 <ul> <li role="treeitem">Chapter 1</l...

import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.IOException; import java.nio.charset.StandardCharsets; import java.nio.file.Files; import java.nio.file.Paths; public class ReadingUTF8TextFile { public static void main(String[] args) throws IOException { ...

import java.nio.charset.StandardCharsets; import java.util.Arrays; public class GetUtf8BytesFromString { public static void main(String[] args) { String str = "Cyrillic symbol Ы"; //StandardCharsets is available since Java 1.7 //for ealier version use ...

When an expression contains multiple operators, it can potentially be read in different ways. For example, the mathematical expression 1 + 2 x 3 could be read in two ways: Add 1 and 2 and multiply the result by 3. This gives the answer 9. If we added parentheses, this would look like ( 1 + 2 )...

If you want to see the schema information of your table, you can use one of the following: SHOW CREATE TABLE child; -- Option 1 CREATE TABLE `child` ( `id` int(11) NOT NULL AUTO_INCREMENT, `fullName` varchar(100) NOT NULL, `myParent` int(11) NOT NULL, PRIMARY KEY (`id`), KEY `momm...

In general, it is considered good practice to throw by value (rather than by pointer), but catch by (const) reference. try { // throw new std::runtime_error("Error!"); // Don't do this! // This creates an exception object // on the heap and would require you to catch the ...

Build numberDescriptionProduct16.0.4366.1000Cumulative Update April 2016SharePoint Server 201616.0.4336.1000RTMSharePoint Server 201616.0.4327.1000Release CandidateSharePoint Server 201616.0.4266.100116.0.4306.1002 Beta 2SharePoint Server 2016

Given a file sample: hello Hello HELLO_there A normal grep for "hello" returns: $ grep "hello" sample hello Using -i allows to ignore case and match any "hello": $ grep -i "hello" sample hello Hello HELLO_there

DBContract.java //Define the tables and columns of your local database public final class DBContract { /*Content Authority its a name for the content provider, is convenient to use the package app name to be unique on the device */ public static final String CONTENT_AUTHORITY =...

A module is an importable file containing definitions and statements. A module can be created by creating a .py file. # hello.py def say_hello(): print("Hello!") Functions in a module can be used by importing the module. For modules that you have made, they will need to be in t...

A Closure is a function taken together with an environment. The function is typically an anonymous function defined inside another function. The environment is the lexical scope of the enclosing function (very basic idea of a lexical scope of a function would be the scope that exists between the fun...

A simple context tree (containing some common values that might be request scoped and included in a context) built from Go code like the following: // Pseudo-Go ctx := context.WithValue( context.WithDeadline( context.WithValue(context.Background(), sidKey, sid), time.Now().A...

A database is created with the following SQL command: CREATE DATABASE myDatabase; This would create an empty database named myDatabase where you can create tables.

When a React component is created, a number of functions are called: If you are using React.createClass (ES5), 5 user defined functions are called If you are using class Component extends React.Component (ES6), 3 user defined functions are called getDefaultProps() (ES5 only) This is the firs...

componentWillUnmount() This method is called before a component is unmounted from the DOM. It is a good place to perform cleaning operations like: Removing event listeners. Clearing timers. Stopping sockets. Cleaning up redux states. componentWillUnmount(){ ... } An example of remo...

With automatic reference counting (ARC), the compiler inserts retain, release, and autorelease statements where they are needed, so you don't have to write them yourself. It also writes dealloc methods for you. The sample program from Manual Memory Management looks like this with ARC: @interface M...

Modern A weak reference looks like one of these: @property (weak) NSString *property; NSString *__weak variable; If you have a weak reference to an object, then under the hood: You're not retaining it. When it gets deallocated, every reference to it will automatically be set to nil Obje...

Send an HTTP response with status code 200 to indicate a successful request. The HTTP response status line is then: HTTP/1.1 200 OK The status text OK is only informative. The response body (message payload) should contain a representation of the requested resource. If there is no representation...

When reading from a file, we want to be able to know when we've reached the end of that file. Knowing that fgets() returns false at the end of the file, we might use this as the condition for a loop. However, if the data returned from the last read happens to be something that evaluates as boolean f...

Haskell has list comprehensions, which are a lot like set comprehensions in math and similar implementations in imperative languages such as Python and JavaScript. At their most basic, list comprehensions take the following form. [ x | x <- someList ] For example [ x | x <- [1..4] ] -...