Tutorial by Examples: d

First why we should use depedency injection in our code ? We want to decouple other components from other classes in our program. For example we have class AnimalController which have code like this : public class AnimalController() { private SantaAndHisReindeer _SantaAndHisReindeer = new San...

autodie allows you to work with files without having to explicitly check for open/close failures. Since Perl 5.10.1, the autodie pragma has been available in core Perl. When used, Perl will automatically check for errors when opening and closing files. Here is an example in which all of the lines ...

VI snippets are like Screenshots of a Block Diagram, with one important difference. They can be opened in LabVIEW to reconstruct the orginal program. They are saved in the common .PNG format so they can be used like normal pictures e.g. in forums and on StackOverflow. To create a VI snippet mark th...

Let's say that you have exam scores for several exams and you want to divide them into quartiles per exam. -- Setup data: declare @values table(Id int identity(1,1) primary key, [Value] float, ExamId int) insert into @values ([Value], ExamId) values (65, 1), (40, 1), (99, 1), (100, 1), (90, 1), ...

Extract all file contents of a zip file import zipfile with zipfile.ZipFile('zipfile.zip','r') as zfile: zfile.extractall('path') If you want extract single files use extract method, it takes name list and path as input parameter import zipfile f=open('zipfile.zip','rb') zfile=zipfile.Z...

This topic demonstrates how to use functions like withColumn, lead, lag, Level etc using Spark. Spark dataframe is an sql abstract layer on spark core functionalities. This enable user to write SQL on distributed data. Spark SQL supports hetrogenous file formats including JSON, XML, CSV , TSV etc. ...

Prerequisites: Apple Developers Account Setup GameCenter Leaderboards with iTunesConnect Setting up GameCenter Leaderboards: Sign in to iTunesConnect Go to My Apps. Create an app for your project then go to Features. Click on Game Center Click the plus sign next to Leaderboards. Choose...

public static Expression<Func<T, bool>> GetExpression<T>(IList<QueryFilter> filters) { Expression exp = null; // Represents a named parameter expression. {parm => parm.Name.Equals()}, it is the param part // To create a ParameterExpression need the ty...

For one filter: Here is where the query is created, it receives a expression parameter and a filter. private static Expression GetExpression<T>(ParameterExpression param, QueryFilter queryFilter) { // Represents accessing a field or property, so here we are accessing for example: ...

ConstantExpression must be the same type of the MemberExpression. The value in this example is a string, which is converted before creating the ConstantExpression instance. private static ConstantExpression GetConstant(Type type, string value) { // Discover the type, convert it, and create Co...

In this very first example, a basic serial write operation is started from an Arduino device. void setup() { // put your setup code here, to run once: Serial.begin(9600); } void loop() { // put your main code here, to run repeatedly: Serial.println("Hello World!"); dela...

/** *@NApiVersion 2.x *@NScriptType Suitelet */ define([],function() { // NetSuite's AMD pattern function onRequest_entry(context) { // Suitelet entry function receives a context obj context.response.write('Hello World'); // Write a response using the context obj } retu...

If you want to append a series of values [1,2] to the column of dataframe df, you will get NaNs: import pandas as pd series=pd.Series([1,2]) df=pd.DataFrame(index=[3,4]) df['col']=series df col 3 NaN 4 NaN because setting a new column automatically aligns the data by the inde...

COMPUTE answer = 3*var-1 That is a reference to the variable var-1, and not var - 1. COMPUTE answer = 3 * var - 1 Recommended, opinion.

Scenario: You need to select an implementation of address validation when a sales order is submitted, and the validator is determined by the country to which the order is shipping. The factory needs to inspect some value passed as an argument to select the correct implementation. First, write an in...

const Promise = require('bluebird'), fs = require('fs') Promise.promisifyAll(fs) // now you can use promise based methods on 'fs' with the Async suffix fs.readFileAsync('file.txt').then(contents => { console.log(contents) }).catch(err => { console.error('error reading', er...

This example shows the simplest usage of the Image component to display an image. The Image source property is a url type that can be either a file with an absolute or relative path, an internet URL (http://) or a Qt resource (qrc:/) import QtQuick 2.3 Rectangle { width: 640 height: 4...

function somethingThatReturnsADisposableResource() { return getSomeResourceAsync(...).disposer(resource => { resource.dispose() }) } Promise.using(somethingThatReturnsADisposableResource(), resource => { // use the resource here, the disposer will automatically close it when ...

const Koa = require('koa') const app = new Koa() app.use(async ctx => { ctx.body = 'Hello World' }) app.listen(8080)

app.use(async (ctx, next) => { try { await next() // attempt to invoke the next middleware downstream } catch (err) { handleError(err, ctx) // define your own error handling function } })