Tutorial by Examples: v

With a simple for loop, all zip archives in a directory can be extracted. for (i in dir(pattern=".zip$")) unzip(i) The dir function produces a character vector of the names of the files in a directory matching the regex pattern specified by pattern. This vector is looped through w...

The following regex includes 50 states and also Commonwealth/Territory (see www.50states.com): regex <- "(A[LKSZR])|(C[AOT])|(D[EC])|(F[ML])|(G[AU])|(HI)|(I[DLNA])|(K[SY])|(LA)|(M[EHDAINSOT])|(N[EVHJMYCD])|(MP)|(O[HKR])|(P[WAR])|(RI)|(S[CD])|(T[NX])|(UT)|(V[TIA])|(W[AVIY])" For exampl...

The following regular expression: us.phones.regex <- "^\\s*(\\+\\s*1(-?|\\s+))*[0-9]{3}\\s*-?\\s*[0-9]{3}\\s*-?\\s*[0-9]{4}$" Validates a phone number in the form of: +1-xxx-xxx-xxxx, including optional leading/trailing blanks at the beginning/end of each group of numbers, but not ...

Goto accepts the use of variable value to act as the label to goto. Example: @echo off echo a = 1 echo b = 2 set /p "foo=Enter option:" goto %foo% However, you should check the input so it will not go to somewhere that does not exist. Going to an undefined label will terminate...

Note in this example we will use PostgreSQL DBMS, but you can use any DBMS We will use a database bd_test witch contain a Schema: sch_test and two tables users and test : CREATE TABLE sch_test.users ( id serial NOT NULL, username character varying, password character varying, CONSTRAI...

The new Bootstrap 4 Navbar Component is improved over it’s Bootstrap 3.x predecessor. In Bootstrap 4, the Navbar is responsive by default and utilizes flexbox to make alignment of Navbar content much easier. It’s also a simple matter of using the new navbar-toggleable-* classes to change the Navbar ...

Suppose we'd like to wrap the Google Maps JavaScript API google.maps: @JS('google.maps') library maps; import "package:js/js.dart"; @JS() class Map { external Map(Location location); external Location getLocation(); } We now have the Map Dart class which corresponds to t...

import android.os.Bundle; import android.os.Handler; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.LinearLayoutManager; import android.support.v7.widget.RecyclerView; import android.support.v7.widget.Toolbar; import android.util.Log; import android.widget.T...

Step 1 - installing VirtualBox Download and install VirtualBox according to your operating system. , it is required to run Genymotion. Step 2 - downloading Genymotion Go to the Genymotion download page and download Genymotion according to your operating system. Note: you will need to create a ...

Call this function with parameter argument as array with type 'any'. It will return you json string. Json string is used to submit array in web service call as request input parameter in Swift. //----------------------- let array = [["one" : 1], ["two" : 2], ["three" ...

Using the magick command (or `convert for IM 6.x users) you con convert any image format to any other. with no other arguments, as little processing as possible will be done to move from one format to the other. Simply specify your input and output files. To convert a JPEG to a PNG: $ magick image....

Event Type- DDL_COMMAND_START DDL_COMMAND_END SQL_DROP This is example for creating an Event Trigger and logging DDL_COMMAND_START events. CREATE TABLE TAB_EVENT_LOGS( DATE_TIME TIMESTAMP, EVENT_NAME TEXT, REMARKS TEXT ); CREATE OR REPLACE FUNCTION FN_LOG_EVENT() RETURNS EVE...

var="hello" function foo(){ echo $var } foo Will obviously output "hello", but this works the other way around too: function foo() { var="hello" } foo echo $var Will also output "hello"

function foo() { local var var="hello" } foo echo $var Will output nothing, as var is a variable local to the function foo, and its value is not visible from outside of it.

Physics is the natural science that involves the study of matter and its motion and behaviour through space and time, along with related concepts such as energy and force. The main goal of physics is to understand how the universe behaves. In a StackOverflow context physics usually refers to simul...

$rootId = Mage::app()->getStore($storeId)->getRootCategoryId(); $categories = Mage::getModel('catalog/category')->getCollection() ->addAttributeToSelect('*') ->addFieldToFilter('path', array('like'=> "1/$rootId/%")) ->addAttributeToFilter('level', 2...

go env [var ...] prints go environment information. By default it prints all the information. $go env GOARCH="amd64" GOBIN="" GOEXE="" GOHOSTARCH="amd64" GOHOSTOS="darwin" GOOS="darwin" GOPATH="/Users/vikashkv/work" ...

Suppose we want to write a constraint which matches a number, but approximatively. Say, you are supposed to have 95 people in a survey, but 93 or 96 will do as well. We can write a custom constraint of the form: public class AlmostEqualToConstraint : Constraint { readonly int _expected; ...

Let's say we have some server that registers new users and greets them with some message. And we want to monitor this server and change some of it's parameters. First, we need an interface with our monitoring and control methods public interface UserCounterMBean { long getSleepTime(); ...

Let's take an scenario to understand advance function in better way, struct User { var name: String var age: Int var country: String? } //User's information let user1 = User(name: "John", age: 24, country: "USA") let user2 = User(name: "Chan", age...