To avoid repetition in nested routes, concerns provide a great way of sharing common resources that are reusable. To create a concern use the method concern within the routes.rb file. The method expects a symbol and block:
concern :commentable do
resources :comments
end
While not creating a...
When assigning named methods to delegates, they will refer to the same underlying object if:
They are the same instance method, on the same instance of a class
They are the same static method on a class
public class Greeter
{
public void WriteInstance()
{
Console.Write...
<?php
switch ($condition):
case $value:
do_something();
break;
default:
do_something_else();
break;
endswitch;
?>
<?php switch ($condition): ?>
<?php case $value: /* having whitespace before your cases will cause an error */ ?&g...
Python uses the C3 linearization algorithm to determine the order in which to resolve class attributes, including methods. This is known as the Method Resolution Order (MRO).
Here's a simple example:
class Foo(object):
foo = 'attr foo of Foo'
class Bar(object):
foo = 'attr foo o...
To change the default stack order positioned elements (position property set to relative, absolute or fixed), use the z-index property.
The higher the z-index, the higher up in the stacking context (on the z-axis) it is placed.
Example
In the example below, a z-index value of 3 puts green on to...
Let's create our own error type for this example.
2.2
enum CustomError: ErrorType {
case SomeError
case AnotherError
}
func throwing() throws {
throw CustomError.SomeError
}
3.0
enum CustomError: Error {
case someError
case anotherError
}
func throwing() thr...
If you are using the default bash prompt on Linux, you should see the name of the virtual environment at the start of your prompt.
(my-project-env) user@hostname:~$ which python
/home/user/my-project-env/bin/python
In order to specify which version of python the Linux shell should use the first line of Python scripts can be a shebang line, which starts with #!:
#!/usr/bin/python
If you are in a virtual environment, then python myscript.py will use the Python from your virtual environment, but ./myscript.py...
In Rails, you find yourself looking at controllers, views, and models for your database.
To reduce the need for heavy configuration, Rails implements rules to ease up working with the application. You may define your own rules but for the beginning (and for later on) it's a good idea to stick to co...
The default value for an enum is zero. If an enum does not define an item with a value of zero, its default value will be zero.
public class Program
{
enum EnumExample
{
one = 1,
two = 2
}
public void Main()
{
var e =...
Now that the router is configured and our app knows how to handle the routes, we need to show the actual components that we configured.
To do so, configure your HTML template/file for your top-level (app) component like so:
//app.ts
import {Component} from '@angular/core';
import {Router, ROUT...
NOTE: This example is based on the 3.0.0.-beta.2 release of the @angular/router. At the time of writing, this is the latest version of the router.
To use the router, define routes in a new TypeScript file like such
//app.routes.ts
import {provideRouter} from '@angular/router';
import {Home} ...
Imaginary numbers in Python are represented by a "j" or "J" trailing the target number.
1j # Equivalent to the square root of -1.
1j * 1j # = (-1+0j)
git cherry-pick <commit-A>..<commit-B> will place every commit after A and up to and including B on top of the currently checked-out branch.
git cherry-pick <commit-A>^..<commit-B> will place commit A and every commit up to and including B on top of the currently checked-out...
