Tutorial by Examples: i

The charset attribute specifies the character encoding for the HTML document and needs to be a valid character encoding (examples include windows-1252, ISO-8859-2, Shift_JIS, and UTF-8). UTF-8 (Unicode) is the most widely used and should be used for any new project. 5 <meta charset="UTF-8...

To refresh the page every five seconds, add this meta element in the head element: <meta http-equiv="refresh" content="5"> CAUTION! While this is a valid command, it is recommended that you do not use it because of its negative effects on user experience. Refreshing the...

git diff 1234abc..6789def # old new E.g.: Show the changes made in the last 3 commits: git diff @~3..@ # HEAD -3 HEAD Note: the two dots (..) is optional, but adds clarity. This will show the textual difference between the commits, regardless of where they are in the tree.

Firstly, make sure that the agent being used has the following attributes in the Manifest.mf: Can-Redefine-Classes: true Can-Retransform-Classes: true Starting a java agent will let the agent access the class Instrumentation. With Instrumentation you can call addTransformer(ClassFileTransformer...

Agents can be added to a JVM at runtime. To load an agent you will need to use the Attach API's VirtualMachine.attatch(String id). You can then load a compiled agent jar with the following method: public static void loadAgent(String agentPath) { String vmName = ManagementFactory.getRuntimeMXBe...

The Premain class will contain the method "premain(String agentArgs Instrumentation inst)" Here is an example: import java.lang.instrument.Instrumentation; public class PremainExample { public static void premain(String agentArgs, Instrumentation inst) { System.out.print...

fn main() { let english = "Hello, World!"; println!("{}", &english[0..5]); // Prints "Hello" println!("{}", &english[7..]); // Prints "World!" } Note that we need to use the & operator here. It takes a reference and ...

A very useful feature of Swift 2.2 is having the ability of extending protocols. It works pretty much like abstract classes when regarding a functionality you want to be available in all the classes that implements some protocol (without having to inherit from a base common class). protocol FooPro...

If you are running Docker on OS X or Windows, docker-compose should be included in your Docker for Windows or Docker Toolbox installation. On Linux you can get the latest binaries straight from the GitHub release page: https://github.com/docker/compose/releases You can install the specific releas...

let list1 = [ 1; 2 ] let list2 = [ 1 .. 100 ] // Accessing an element printfn "%A" list1.[0] // Pattern matching let rec patternMatch aList = match aList with | [] -> printfn "This is an empty list" | head::tail -> printfn "This list consists o...

Create a .gitattributes file in the project root containing: * -text This is equivalent to setting core.autocrlf = false.

Create a .gitattributes file in the project root containing: * text=auto This will result in all text files (as identified by Git) being committed with LF, but checked out according to the host operating system default. This is equivalent to the recommended core.autocrlf defaults of: input o...

When contributors add to a project from different machines or operating systems, it may happen that they use different email addresses or names for this, which will fragment contributor lists and statistics. Running git shortlog -sn to get a list of contributors and the number of commits by them co...

Whenever an object is treated as a string, the __toString() method is called. This method should return a string representation of the class. class User { public $first_name; public $last_name; public $age; public function __toString() { return "{$this->first_...

This example is showing how to query a database with database/sql, taking as example a MySql database. package main import ( "log" "fmt" "database/sql" _ "github.com/go-sql-driver/mysql" ) func main() { dsn := "mysql_usern...

Generally speaking, empty commits (or commits with state that is identical to the parent) is an error. However, when testing build hooks, CI systems, and other systems that trigger off a commit, it's handy to be able to easily create commits without having to edit/touch a dummy file. The --allow-e...

It's a very common extension that allows type classes with multiple type parameters. You can think of MPTC as a relation between types. {-# LANGUAGE MultiParamTypeClasses #-} class Convertable a b where convert :: a -> b instance Convertable Int Float where convert i = fromIntegr...

Regular instances require: All instance types must be of the form (T a1 ... an) where a1 ... an are *distinct type variables*, and each type variable appears at most once in the instance head. That means that, for example, while you can create an instance for [a] you can't create an instance f...

Normally, string literals in Haskell have a type of String (which is a type alias for [Char]). While this isn't a problem for smaller, educational programs, real-world applications often require more efficient storage such as Text or ByteString. OverloadedStrings simply changes the type of literals...

A syntactic extension that allows applying the tuple constructor (which is an operator) in a section way: (a,b) == (,) a b -- With TupleSections (a,b) == (,) a b == (a,) b == (,b) a N-tuples It also works for tuples with arity greater than two (,2,) 1 3 == (1,2,3) Mapping This can be u...