Tutorial by Examples: an

Java applets are able to load different resources. But since they are running in the web browser of the client you need to make sure that these resources are accessible. Applets are not able to access client resources as the local file system. If you want to load resources from the same URL the App...

Common Lisp does not have interfaces in the sense that some languages (e.g., Java) do, and there is less need for that type of interface given that Common Lisp supports multiple inheritance and generic functions. However, the same type of patterns can be realized easily using mixin classes. This e...

Let's say we have a table team_person as below: +======+===========+ | team | person | +======+===========+ | A | John | +------+-----------+ | B | Smith | +------+-----------+ | A | Walter | +------+-----------+ | A | Louis | +------+-----------+ | C | ...

To install the software: After the download completes, run the installer. For Windows, the installer executable file has the .exe extension. Double-click the installer file to run it. For Linux platforms, the installer file has the .sh extension. For these platforms, you need to make ...

The ROLLUP operator is useful in generating reports that contain subtotals and totals. CUBE generates a result set that shows aggregates for all combinations of values in the selected columns. ROLLUP generates a result set that shows aggregates for a hierarchy of values in the selected col...

The most important thing for speeding up a query on any non-tiny table is to have a suitable index. WHERE a = 12 --> INDEX(a) WHERE a > 12 --> INDEX(a) WHERE a = 12 AND b > 78 --> INDEX(a,b) is more useful than INDEX(b,a) WHERE a > 12 AND b > 78 --> INDEX(a) or INDE...

import { NgModule } from '@angular/core'; @NgModule({ declarations: [], // components your module owns. imports: [], // other modules your module needs. providers: [], // providers available to your module. bootstrap: [] // bootstrap this root component. }) export class MyModule {} ...

Sometimes we need to perform basic operations like hide/show view based on single value, for that single variable we cannot create model or it is not good practice to create model for that. DataBinding supports basic datatypes to perform those oprations. <layout xmlns:android="http://schema...

First Initialize FirebaseDatabase: FirebaseDatabase database = FirebaseDatabase.getInstance(); Write to your database: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRef....

app.ts import {Component} from '@angular/core'; import {Platform, ionicBootstrap} from 'ionic-angular'; import {StatusBar} from 'ionic-native'; import {LoginPage} from './pages/login/login'; import {FIREBASE_PROVIDERS, defaultFirebase, AuthMethods, AuthProviders, firebaseAuthConfig} from 'angul...

Joining Two Paths Paths can be joined using the resolve() method. The path passed has to be a partial path, which is a path that doesn't include the root element. Path p5 = Paths.get("/home/"); Path p6 = Paths.get("arthur/files"); Path joined = p5.resolve(p6); Path otherJoi...

So, you have completed installation it's time now to Run you program with it. Netbeans has created a shortcut to your desktop, "Double click" that to open the IDE. To Create a new project 1. Click this button OR Goto: files >> New Project then this window will popup Select...

This implementation of IDatabaseInitializer drops and recreates the database if the model changes automatically. Usage: public class MyContext : DbContext { public MyContext() { Database.SetInitializer(new DropCreateDatabaseIfModelChanges<MyContext>()); } }

Transformations alter a given point's starting position by moving, rotating & scaling that point. Translation: Moves a point by a distanceX and distanceY. Rotation: Rotates a point by a radian angle around it's rotation point. The default rotation point in Html Canvas is the top-left origin ...

Canvas allows you to context.translate, context.rotate and context.scale in order to draw your shape in the position & size you require. Canvas itself uses a transformation matrix to efficiently track transformations. You can change Canvas's matrix with context.transform You can change Canv...

Spark uses lazy evaluation; that means it will not do any work, unless it really has to. That approach allows us to avoid unnecessary memory usage, thus making us able to work with big data. A transformation is lazy evaluated and the actual work happens, when an action occurs. Example: In [1]: li...

Plenty has been written about Python's GIL. It can sometimes cause confusion when dealing with multi-threaded (not to be confused with multiprocess) applications. Here's an example: import math from threading import Thread def calc_fact(num): math.factorial(num) num = 600000 t = Threa...

In most object oriented languages, allocating memory for an object and initializing it is an atomic operation: // Both allocates memory and calls the constructor MyClass object = new MyClass(); In Objective-C, these are separate operations. The class methods alloc (and its historic sibling allo...

Data frames are R's tabular data structure. They can be written to or read from in a variety of ways. This example illustrates a couple common situations. See the links at the end for other resources. Writing Before making the example data below, make sure you're in a folder you want to write to....

This example uses C++14 and boost::any. In C++17 you can swap in std::any instead. The syntax we end up with is: const auto print = make_any_method<void(std::ostream&)>([](auto&& p, std::ostream& t){ t << p << "\n"; }); super_any<decltype(print...