Tutorial by Examples: rom

Skipping some rows from result

ISO/ANSI SQL: SELECT Id, Col1 FROM TableName ORDER BY Id OFFSET 20 ROWS MySQL: SELECT * FROM TableName LIMIT 20, 42424242424242; -- skips 20 for take use very large number that is more than rows in table Oracle: SELECT Id, Col1 FROM (SELECT Id, Col1, row_num...

SQL • SKIP TAKE (Pagination)

Removing the Admin Toolbar from all except Administrators

Add the following code to functions.php to remove it from everyone except the Administrator user level: add_action('after_setup_theme', 'no_admin_bar'); function no_admin_bar() { if (!current_user_can('administrator') && !is_admin()) { show_admin_bar(false); ...

WordPress • The Admin Bar (aka "The Toolbar")

Copy to clipboard from textarea using execCommand("copy")

Example: <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title></title> </head> <body> <textarea id="content"></textarea> <input type="button" id="copy...

JavaScript • execCommand and contenteditable

Extracting a list of names from a list of Person(s)

Given a Person struct struct Person { let name: String let birthYear: Int? } and an Array of Person(s) let persons = [ Person(name: "Walter White", birthYear: 1959), Person(name: "Jesse Pinkman", birthYear: 1984), Person(name: "Skyler White&quo...

Swift Language • Functional Programming in Swift

Using std::move to reduce complexity from O(n²) to O(n)

C++11 introduced core language and standard library support for moving an object. The idea is that when an object o is a temporary and one wants a logical copy, then its safe to just pilfer o's resources, such as a dynamically allocated buffer, leaving o logically empty but still destructible and co...

C++ • Move Semantics

Using a DATABASE_URL from the environment

In PaaS sites such as Heroku, it is usual to receive the database information as a single URL environment variable, instead of several parameters (host, port, user, password...). There is a module, dj_database_url which automatically extracts the DATABASE_URL environment variable to a Python dictio...

Django • Settings

Read Data from TextFile with Streams

I/O in node is asynchronous, so interacting with the disk and network involves passing callbacks to functions. You might be tempted to write code that serves up a file from disk like this: var http = require('http'); var fs = require('fs'); var server = http.createServer(function (req, res) { ...

Node.js • Using Streams

Combining two arrays (keys from one, values from another)

The following example shows how to merge two arrays into one associative array, where the key values will be the items of the first array, and the values will be from the second: $array_one = ['key1', 'key2', 'key3']; $array_two = ['value1', 'value2', 'value3']; $array_three = array_combine($ar...

PHP • Processing Multiple Arrays Together

Instantiate from a Storyboard

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil]; With an Identifier: Give the scene a Storyboard ID within the identity inspector of the storyboard. Instantiate in code: UIViewController *controller = [storyboard instantiateViewControllerWithIdentifi...

iOS • UIViewController

Convert NSDate that is composed from hour and minute (only) to a full NSDate

There are many cases when one has created an NSDate from only an hour and minute format, i.e: 08:12 that returns from a server as a String and you initiate an NSDate instance by these values only. The downside for this situation is that your NSDate is almost completely "naked" and what yo...

iOS • NSDate

Store, Retrieve, Remove and Clear Data from SharedPreferences

Create SharedPreferences BuyyaPref SharedPreferences pref = getApplicationContext().getSharedPreferences("BuyyaPref", MODE_PRIVATE); Editor editor = pref.edit(); Storing data as KEY/VALUE pair editor.putBoolean("key_name1", true); // Saving boolean - true/false ...

Android • SharedPreferences

Intercepting calls from your app even from the background

From Apple documentation: Use the CTCallCenter class to obtain a list of current cellular calls, and to respond to state changes for calls such as from a dialing state to a connected state. Such state changes are known as cellular call events. The purpose of CTCallCenter is to give the develop...

iOS • CTCallCenter

Arithmetic promotions and conversions

Converting an integer type to the corresponding promoted type is better than converting it to some other integer type. void f(int x); void f(short x); signed char c = 42; f(c); // calls f(int); promotion to int is better than conversion to short short s = 42; f(s); // calls f(short); exact mat...

C++ • Overload resolution

Migrate from SVN to Git using Atlassian conversion utility

Download the Atlassian conversion utility here. This utility requires Java, so please ensure that you have the Java Runtime Environment JRE installed on the machine you plan to do the conversion. Use the command java -jar svn-migration-scripts.jar verify to check if your machine is missing any of t...

Git • Migrating to Git

Creating input streams from strings

The macro WITH-INPUT-FROM-STRING can be used to make a stream from a string. (with-input-from-string (str "Foobar") (loop for i from 0 for char = (read-char str nil nil) while char do (format t "~d: ~a~%" i char))) ; 0: F ; 1: o ; 2: o ; 3: b ;...

common-lisp • Streams

Using JsonReader to read JSON from a stream

JsonReader reads a JSON encoded value as a stream of tokens. public List<Message> readJsonStream(InputStream in) throws IOException { JsonReader reader = new JsonReader(new InputStreamReader(in, "UTF-8")); try { return readMessagesArray(reader); } finall...

Android • JSON in Android with org.json

Use of Split to create an array from a string

Split Function returns a zero-based, one dimensional array containing a specified number of substrings. Syntax Split(expression [, delimiter [, limit [, compare]]]) PartDescriptionexpressionRequired. String expression containing substrings and delimiters. If expression is a zero-length string(&q...

VBA • Arrays

Array from string

stringVar="Apple Orange Banana Mango" arrayVar=(${stringVar// / }) Each space in the string denotes a new item in the resulting array. echo ${arrayVar[0]} # will print Apple echo ${arrayVar[3]} # will print Mango Similarly, other characters can be used for the delimiter. stringVa...

Bash • Arrays

Using Pluck to extract certain values from a collection

You will often find yourself with a collection of data where you are only interested in parts of the data. In the example below we got a list of participants at an event and we want to provide a the tour guide with a simple list of names. // First we collect the participants $participants = colle...

Laravel • Collections

Passing Data from parent to child with props

In Vue.js, every component instance has its own isolated scope, which means that if a parent component has a child component - the child component has its own isolated scope and the parent component has its own isolated scope. For any medium to large size app, following best practices conventions p...

Vue.js • Props