Tutorial by Examples: e

Over time, our classes may implement more and more interfaces. When these interfaces have many methods, the total number of methods in our class will become very large. For example, let's suppose that we have two interfaces and a class implementing them: interface Printable { public functio...

file is no longer a builtin name in 3.x (open still works). Internal details of file I/O have been moved to the standard library io module, which is also the new home of StringIO: import io assert io.open is open # the builtin is an alias buffer = io.StringIO() buffer.write('hello, ') # returns...

import cv2 image_path= #put your image path here #use imread() function to read image data to variable img. img = cv2.imread(image_path) #display image data in a new window with title 'I am an image display window' cv2.imshow('I am an image display window',img) #wait until user hi...

Java Logging Api has 7 levels. The levels in descending order are: SEVERE (highest value) WARNING INFO CONFIG FINE FINER FINEST (lowest value) The default level is INFO (but this depends on the system and used a virtual machine). Note: There are also levels OFF (can be used to turn log...

The if statement is used to control the flow of the program. An if statement identifies which statement to run based on the value of a Boolean expression. For a single statement, the braces{} are optional but recommended. int a = 4; if(a % 2 == 0) { Console.WriteLine("a contains an...

CREATE TABLE stack( id INT, username VARCHAR(30) NOT NULL, password VARCHAR(30) NOT NULL ); INSERT INTO stack (`id`, `username`, `password`) VALUES (1, 'Foo', 'hiddenGem'); INSERT INTO stack (`id`, `username`, `password`) VALUES (2, 'Baa', 'verySecret'); Query SELECT id FROM ...

Query SELECT * FROM stack; Result +------+----------+----------+ | id | username | password | +------+----------+----------+ | 1 | admin | admin | | 2 | stack | stack | +------+----------+----------+ 2 rows in set (0.00 sec) You can select all columns from one table...

Query SELECT * FROM stack WHERE username = "admin" AND password = "admin"; Result +------+----------+----------+ | id | username | password | +------+----------+----------+ | 1 | admin | admin | +------+----------+----------+ 1 row in set (0.00 sec) Query...

CREATE TABLE stack ( id int AUTO_INCREMENT PRIMARY KEY, username VARCHAR(100) NOT NULL ); INSERT stack(username) VALUES ('admin'),('k admin'),('adm'),('a adm b'),('b XadmY c'), ('adm now'), ('not here'); "adm" anywhere: SELECT * FROM stack WHERE username LIKE "%adm%&q...

SQL aliases are used to temporarily rename a table or a column. They are generally used to improve readability. Query SELECT username AS val FROM stack; SELECT username val FROM stack; (Note: AS is syntactically optional.) Result +-------+ | val | +-------+ | admin | | stack | +----...

It's also possible to use data binding within your RecyclerView Adapter. Data model public class Item { private String name; public String getName() { return name; } } XML Layout <TextView android:layout_width="wrap_content" android:layou...

With the ~ selector, you can easily implement a global accessible boolean without using JavaScript. Add boolean as a checkbox To the very beginning of your document, add as much booleans as you want with a unique id and the hidden attribute set: <input type="checkbox" id="sideba...

The horizontally justified navigation (menu) bar has some number of items that should be justified. The first (left) item has no left margin within the container, the last (right) item has no right margin within the container. The distance between items is equal, independent on the individual item w...

The backface-visibility property relates to 3D transforms. With 3D transforms and the backface-visibility property, you're able to rotate an element such that the original front of an element no longer faces the screen. For example, this would flip an element away from the screen: JSFIDDLE <d...

C++11 The C++11 standards guarantees that the initialization of function scope objects are initialized in a synchronized manner. This can be used to implement a thread-safe singleton with lazy initialization. class Foo { public: static Foo& instance() { static Foo inst; ...

This is a simple application with primefaces, it is a login page: 1-Configuration of web.xml: <?xml version="1.0" encoding="UTF-8"?> <web-app version="3.1" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-...

Suppose you have complex code that creates and returns a list by starting with a blank list and repeatedly appending to it: def create(): result = [] # logic here... result.append(value) # possibly in several places # more logic... return result # possibly in several places...

Clojure functions can be defined with zero or more parameters. (defn welcome "Without parameters" [] "Hello!") (defn square "Take one parameter" [x] (* x x)) (defn multiplier "Two parameters" [x y] (* x y)) ...

First, Install gulp and gulp-concat plugin to your project localy npm install --save-dev gulp gulp-concat and add gulp-concat task to your gulpfile.js var gulp = require('gulp'); var concat = require('gulp-concat'); gulp.task('default', function() { }); gulp.task('css', function() { ...

First, Install gulp, gulp-clean-css and gulp-rename to project directory localy npm install --save-dev gulp gulp-clean-css gulp-rename Than add following minify-css task to your gulpfile.js var gulp = require('gulp'); var cleanCSS = require('gulp-clean-css'); var rename = require('gulp-rename...