10 digit regex ruby (for phone numbers)
How to check for 10 (ten) digits, no more, no less, using regular expression in ruby on rails with ruby:
:with => /^\d{10,10}$/
useful for american phone numbers.
Announcing: Monthly Payment Calculator by app79
This is actually just a small part of a bigger application I'm working on, but it's useful by itself so I'm posting it.
Figure out how much your soul car or house will cost you every month with the easy to use Monthly Payment Calculator! Works with Silverlight 2 Beta 2 on Firefox/IE/Not Google Chrome. Available now at http://app79.com/live/payment/
Screenshot
Announcing: Market Rate Calculator by app79
For all your salary comparison needs, takes up to 2 salaries and returns the market rate +/- 15% and 30%. Market Rate Calculator runs on Silverlight 2 beta 2 (Mac/PC compatible), comes with no guarantee of getting you a raise, and is available now at http://app79.com/live/marketrate.
Screenshot:
On/Off, C#, and Ternary Logic
This past week I've been working on a step sequencer built in Silverlight. One of the requirements was that a 'step' change to a different color when it is active ( an on/off switch ). The simplest solution is this piece of code:
if (currentStatus == on)
{
status = off
}
else
{
status = on
}
While this works, it can be made more elegant using a ternary operator, and rewritten with just one line of code:
status = currentStatus == on ? off : on;
which in my case translates to:
myButton.Background = currentBrush.Color == greenBrush.Color ? blueBrush : greenBrush;
Again, this just says, if the current brush is green (currentBrush.Color == greenBrush.Color) make the background (myButton.Background) blue, else make it green.
Design Patterns 101
Principles
1) Program to an interface rather than an implementation.
2) Composition and delegation result in runtime flexibility and should be favored to inheritance.
3) Find out what varies and encapsulate it.
Types of Patterns
:: Creational (factory, prototype, singleton)
:: Structural (adapter, proxy, façade)
:: Behavioral ( State, Visitor, Template Method, Strategy)
Notes
- Good when used correctly
- Bad when used like hammer with no nails