Tutorial by Examples: code

DeviceFamily specific code

In general, UWP is used for making a single application that runs on Windows 10 across many different devices. However, it is also possible to make code tailored to specific devices. You can achieve this in several different ways. Different XAML Layout If you want to use a specific layout on for a...

uwp • Device Families

Difference between jQuery(fn) and executing your code before

Using the document-ready event can have small performance drawbacks, with delayed execution of up to ~300ms. Sometimes the same behavior can be achieved by execution of code just before the closing </body> tag: <body> <span id="greeting"></span> world! <sc...

jQuery • document-ready event

Error code 1215: Cannot add foreign key constraint

This error occurs when tables are not adequately structured to handle the speedy lookup verification of Foreign Key (FK) requirements that the developer is mandating. CREATE TABLE `gtType` ( `type` char(2) NOT NULL, `description` varchar(1000) NOT NULL, PRIMARY KEY (`type`) ) ENGINE=InnoD...

MySQL • Error codes

Context. Using a credential cache for elevated execution of code

While server side-code can run with elevated privileges, there is not an equivalent method to elevate privileges in client-side code (for obvious security reasons). As an alternative, you can specify credentials to emulate the access of a specific user or service account. To specify credentials, bu...

sharepoint • Working with Managed Client Side Object Model (CSOM)

Adding behaviour by adding classes without touching existing code

import java.util.ArrayList; import java.util.List; import static java.lang.System.out; public class PolymorphismDemo { public static void main(String[] args) { List<FlyingMachine> machines = new ArrayList<FlyingMachine>(); machines.add(new FlyingMachine())...

Java Language • Polymorphism

Checking if a required gem is installed from within code

To check if a required gem is installed, from within your code, you can use the following (using nokogiri as an example): begin found_gem = Gem::Specification.find_by_name('nokogiri') require 'nokogiri' .... <the rest of your code> rescue Gem::LoadError end However, this can ...

Ruby Language • Gem Usage

Unicode

Returns the integer value representing the Unicode value of the first character of the input expression. Parameters: Unicode character expression. Any valid nchar or nvarchar expression. SELECT UNICODE(N'Ɛ') -- Returns 400 DECLARE @Unicode nvarchar(11) = N'Ɛ is a char' SELECT UNICODE(@Uni...

Microsoft SQL Server • String Functions

Comments in code

Transact-SQL supports two forms of comment writing. Comments are ignored by the database engine, and are meant for people to read. Comments are preceded by -- and are ignored until a new line is encountered: -- This is a comment SELECT * FROM MyTable -- This is another comment WHERE Id = 1; ...

Microsoft SQL Server • Getting started with Microsoft SQL Server

.Rprofile - the first chunk of code executed

.Rprofile is a file containing R code that is executed when you launch R from the directory containing the .Rprofile file. The similarly named Rprofile.site, located in R's home directory, is executed by default every time you load R from any directory. Rprofile.site and to a greater extend .Rprofil...

R Language • .Rprofile

Visual Format Language Basics: Constraints in Code!

HVFL is a language designed to constrain UI elements in a simple and quick fashion. Generally, VFL has an advantage over traditional UI customization in the Interface Builder because it's much more readable, accessible and compact. Here's an example of VFL, in which three UIViews are constrained f...

iOS • Auto Layout

R in Latex with Knitr and Code Externalization

Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is external code chunks. External code chunks allow us to develop/test R Scripts in an R development environment and then include the results in a report. It is a powerful organizational technique....

R Language • R in LaTeX with knitr

How to remove the index.php from url's with using wamp and codeigniter

First thing to do is enable the mod rewrite on wamp go to Apache modules and scroll down the list If not showing tick enable it and then restart all servers. Linux users can also use below terminal command to enable rewrite module sudo a2enmod rewrite Then restart apache using: sudo service...

codeigniter • Removing index.php using WAMP and CodeIgniter

Place allocation and cleanup code next to each other

Scope guards allow executing statements at certain conditions if the current block is left. import core.stdc.stdlib; void main() { int* p = cast(int*)malloc(int.sizeof); scope(exit) free(p); }

D Language • Scope guards

Indent code properly

Proper indentation gives not only the aesthetic look but also increases the readability of the code. For example, consider the following code: %no need to understand the code, just give it a look n = 2; bf = false; while n>1 for ii = 1:n for jj = 1:n if ii+jj>30 bf = true; break end...

MATLAB Language • MATLAB Best Practices

Display the bytecode of a function

The Python interpreter compiles code to bytecode before executing it on the Python's virtual machine (see also What is python bytecode?. Here's how to view the bytecode of a Python function import dis def fib(n): if n <= 2: return 1 return fib(n-1) + fib(n-2) # Display the disas...

Python Language • Accessing Python source code and bytecode

Exploring the code object of a function

CPython allows access to the code object for a function object. The __code__object contains the raw bytecode (co_code) of the function as well as other information such as constants and variable names. def fib(n): if n <= 2: return 1 return fib(n-1) + fib(n-2) dir(fib.__code__) de...

Python Language • Accessing Python source code and bytecode

Resources from Code-behind

In this example, we'll be accessing three different resources from Code-behind, each stored in a different scope App.xaml: <Application x:Class="WpfSamples.App" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http:/...

wpf • WPF Resources

Reading status codes

The attribute status_code contains the status code of the response good_req = requests.get('https://api.github.com/events') code_200 = good_req.status_code notfound_req = requests.get('https://api.github.com/not_found') code_404 = notfound_req.status_code requests.codes.__dict__ will provid...

python-requests • Getting started with python-requests

Converting Unicode characters to “\uxxxx” format using PHP

You can use the following code for going back and forward. if (!function_exists('codepoint_encode')) { function codepoint_encode($str) { return substr(json_encode($str), 1, -1); } } if (!function_exists('codepoint_decode')) { function codepoint_decode($str) { re...

PHP • Unicode Support in PHP

Converting Unicode characters to their numeric value and/or HTML entities using PHP

You can use the following code for going back and forward. if (!function_exists('mb_internal_encoding')) { function mb_internal_encoding($encoding = NULL) { return ($from_encoding === NULL) ? iconv_get_encoding() : iconv_set_encoding($encoding); } } if (!function_exists('mb_c...

PHP • Unicode Support in PHP