Tutorial by Examples: c

With ASP.NET Core the Microsoft team also introduced the Options pattern, which allows to have strong typed options and once configured the ability to inject the options into your services. First we start with a strong typed class, which will hold our configuration. public class MySettings { ...

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...

If you need to add a property with a null value, you should use the predefined static final JSONObject.NULL and not the standard Java null reference. JSONObject.NULL is a sentinel value used to explicitly define a property with an empty value. JSONObject obj = new JSONObject(); obj.put("some...

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...

When testing for any of several equality comparisons: if a == 3 or b == 3 or c == 3: it is tempting to abbreviate this to if a or b or c == 3: # Wrong This is wrong; the or operator has lower precedence than ==, so the expression will be evaluated as if (a) or (b) or (c == 3):. The correct w...

Check existing remote git remote -v # origin https://github.com/username/repo.git (fetch) # origin https://github.com/usernam/repo.git (push) Changing repository URL git remote set-url origin https://github.com/username/repo2.git # Change the 'origin' remote's URL Verify new remote URL ...

Back references are used to match the same text previously matched by a capturing group. This both helps in reusing previous parts of your pattern and in ensuring two pieces of a string match. For example, if you are trying to verify that a string has a digit from zero to nine, a separator, such as...

ESLint is a code style linter and formatter for your style guide much like JSHint. ESLint merged with JSCS in April of 2016. ESLint does take more effort to set up than JSHint, but there are clear instructions on their website for getting started. A sample configuration for ESLint is as follows: {...

To define the struct called Person with an integer type variable age, integer type variable height and float type variable ageXHeight: struct Person { int age; int height; float ageXHeight; } Generally: struct structName { /+ values go here +/ }

In D we can use constructors to initialize structs just like a class. To define a construct for the struct declared in the previous example we can type: struct Person { this(int age, int height) { this.age = age; this.height = height; this.ageXHeight = cast(float)age...

Verilog is a hardware description language (HDL) used to model electronic systems. It most commonly describes an electronic system at the register-transfer level (RTL) of abstraction. It is also used in the verification of analog circuits and mixed-signal circuits. Its structure and main principles ...

As a good developer you have created following struct with both exported and unexported fields: type MyStruct struct { uuid string Name string } Example in Playground: https://play.golang.org/p/Zk94Il2ANZ Now you want to Marshal() this struct into valid JSON for storage in somet...

As of GHC 7.10, Applicative is a superclass of Monad (i.e., every type which is a Monad must also be an Applicative). All the methods of Applicative (pure, <*>) can be implemented in terms of methods of Monad (return, >>=). It is obvious that pure and return serve equivalent purposes, ...

Module MainPrompt Public Const PromptSymbol As String = "TLA > " Public Const ApplicationTitle As String = GetType(Project.BaseClass).Assembly.FullName REM Or you can use a custom string REM Public Const ApplicationTitle As String = "Short name of the application" Sub M...

Structure for Binary Search Tree (BST) nodes: struct node { int data; node * left; node * right; } Search Algorithm // Check if a value exists in the tree bool BSTSearch(node * current, int value) { if (current->data == value) { return true; } e...

Creates an image representing a gradient of colors radiating from the center of the gradient radial-gradient(red, orange, yellow) /*A gradient coming out from the middle of the gradient, red at the center, then orange, until it is finally yellow at the edges*/

This module defines functions and classes which implement a flexible event logging system for applications and libraries. The key benefit of having the logging API provided by a standard library module is that all Python modules can participate in logging, so your application log can include your o...

--dataset schemas must be identical SELECT 'Data1' as 'Column' UNION ALL SELECT 'Data2' as 'Column' UNION ALL SELECT 'Data3' as 'Column' UNION ALL SELECT 'Data4' as 'Column' UNION ALL SELECT 'Data5' as 'Column' EXCEPT SELECT 'Data3' as 'Column' --Returns Data1, Data2, Data4, and Data5

An example of a RLMObject base model class that uses a primary key and some generic default properties. Subclasses can then set metadata specific to their needs. @interface BaseModel : RLMObject @property NSString *uuid; @property NSString *metadata; @end @implementation BaseModel + (N...

Ruby hashes use the methods hash and eql? to perform the hash operation and assign objects stored in the hash to internal hash bins. The default implementation of hash in Ruby is the murmur hash function over all member fields of the hashed object. To override this behavior it is possible to overrid...