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Inheritance is the core of object-oriented programming. The construction of smaller class structures makes programs easy and great programs possible. In Ruby, inheritance is used to create a relationship between classes that can be used in the code. When a class is a kind of a different class, you can use inheritance to classes of children. ” For example, you could have a form of class. Conducting classes for children of the kind of shape as a circle or square class, using a method that takes an argument could also form a circle as a kind of .

use inheritance in Ruby

starts with a base (or “super”) class. The following example uses a class called Microwave: Microwavedef put_food_in kind (food) @ food = foodenddef food take_food_outfood = @ @ = nilreturn food foodenddef turn_onputs “Microwave is in the” end def turn_off put a microwave is turned endend

Write a class inherited statement. This is the same as a regular class, but adds the “

Add new methods to the class. The class will have all the methods of the superclass, and add additional methods. You can also add new member variables and access attr_ *: class TimedMicrowave

Override methods in the superclass with new methods. As in the previous example was added a timer for the microwave, a method that turn_on automatically turn off the microwave oven can be applied. Simply define a method with the same name as the method of the superclass. When called, the method in the child class will override the method of the superclass. Here, any code that expects to see an object you can use a microwave TimedMicrowave object: class TimedMicrowave 0puts “in Microwave. # ( timer @) second (s) remaining. “timer @ # -= 1sleep 1end We finished cooking, turn the microwave offturn_offendend

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by rows of a MySQL SELECT query are displayed in an arbitrary order or unpredictable. Since the return is more inside and hash algorithms that search for what you do with your data, the order of the rows is generally not useful to a developer. To return the rows of an order, you can use the ORDER BY clause of the SELECT to sort the base .

Form SELECT to return the rows in which you are interested. At this point, the order in which rows are returned is not of importance. This example queries a customer database for a list of customers with negative balances. Example: SELECT * FROM customers WHERE balance <0.0 ;

Add an ORDER BY clause. ORDER BY, MySQL will tell the server to sort the rows by a column. For example, if you want to see all outstanding accounts to balance, you can add “ORDER BY balance” at the end of the consultation. Example: SELECT * FROM customers WHERE balance <0.0 ORDER BY balance ;

Define in which direction to sort, as the order of the rows returned may not yet be meaningful. You can return the rows in ascending or descending order .

use ASC or DESC. Using the ASC order for you to see the smallest number first. DESC using the data type for you to see the largest number first. In this consultation, which seeks customers with the highest negative balance in the first place. ORDER BY return the array with the largest negative number (the smallest) at the top. Example: SELECT * FROM customers WHERE balance <0.0 ORDER BY ASC balance ;

Sort by multiple columns, as sometimes you’ll come across large groups of rows that were ordered in the same issue. For example, if there are 100 customers in its database with a balance of 0, users appear in arbitrary order. It is better to have at least two criteria to classify this type of situation .

Using multiple criteria classification separated by commas. Here, customers are shown in alphabetical order by name after they are sorted by the balance. Example: SELECT * FROM customers WHERE balance <0.0 balance ORDER BY name ASC

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Before HTML 4.0, the properties of the source and the size could be manipulated via the “font” tag. This label is gone. The World Wide Web Consortium (W3C) has removed from its list of recommendations, it is not useful for programmers. The display properties of sources in one site are handled by cascading style sheets (CSS). But because the old “source” tag is still supported, this article focuses on two ways of changing fonts Fonts .

manipulate through the

Open a file HTML in a text editor. Place a “source” inside the tag “body” tags of an HTML page. Write a text between the start and end parts .

Insert a “size” property in the opening tag and give it a value, as shown in the following example. Save the file with the source code then updates the browser and observe the size .

Example :

< body >

< font size = 1 > text

< / body >

Change the value of “size” property in step 2 to 7. Save the source file, monitor and update the announcement of the new font size Through sources .

Handle Style Sheets

Place a “head” and a “point” between the label of “body” tags of an HTML page. These are the newspapers and in the header section of HTML 3.2 tags. Enter the text from the beginning to the end part .

Insert a “style” property on the open part of both. The value of a “style” is the font-size “switch, followed by a colon and followed by one percentage point. The value is within quotes. The size is controlled by the percentage of the figure. Ranging between 0 and has no upper limit. If this is not the number given the size defaults to 100 percent. Save the file with the source code then updates the browser and note the font size .

< body >

< h1 style = "font-size: 120%" > Heading

< p style = "font-size: 50%"> paragraph

< / body >

Change the percentage of values to other number, save and update. The percent has no upper limit, meaning they can exceed 100. Observe how changing the font size.

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Since Python is an interpreted language, the compilation of Python code can mean many things, including the compilation of byte code or conversion to another language. By learning to take Python code and compile it into an executable for Windows platforms, you can create a Python program and Windows users without having to run .

Set

Create your Python program or import into the Windows environment .

Run the code in the Python interpreter and make sure that no errors in the code: c: Python> Python mycode.py

Download py2exe win32 py2exe compiler of the website (see Resources below ).

Save the downloaded file to disk .

Open the downloaded file and click through the installation process. This should take a few seconds. The installation program will create a directory on your py2exe.exe distributed distutils installation of Python code used to create compiled .

compile Python code

Open a new text file in Notepad notes or your favorite editor and save it as mysetupfile.py. This text file will tell the program that py2exe Python programs to become a .

exe Add the following lines in the text file: distutils.core import settings import py2exesetup (console = [ 'mycode . py ']) where “mycode.py” is the name of your Python program you want to compile .

mysetupfile.py Run the file through the program py2exe: c: Python> Python mysetupfile.py py2exe

Wait until the compiler py2exe leaving the finished production. If all goes well, the compiler can inform you of the DLL that the program is dependent on Python once the compilation .

Wait until the compilation is done. Once that is, a directory called “dist” will be created. Enter the directory by type: c: Python> cd dist

Search directory to see an exe of your project. Proof of compiling the program: c: Python> mycode.exe

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compared the value of two fields in ASP VB has never been easier. With a few clicks and drag and some additions, the ASP server will do all the work for you .

Create new website

Start Microsoft Visual Studio 2005 and create a new ASP. NET website. (FILE>> NEW WEBSITE) In this example, the website is called Visual Basic TestSite and saved on the hard disk .

Add two text boxes in

Default.aspx page in Design view, insert two text boxes. TextBox object can be found in the toolbox by default in the “Standard” list. There are two ways to add a TextBox. The first issue is dragging the TextBox from the toolbox to list the location of the page you want the text box seating. The second is first placing the cursor where you want to include TextBox, and then double-click the TextBox object in the toolbox. The example that has used the labels of the text boxes for clarity .

CompareValidator Add

SOURCE Change to review the code. The asp have identification tags and text have been appointed by you, although you are free to change. The CompareValidator can add more or less anywhere on your page. Again, for clarity, in the example, was added to the right of “ComparisonValidator Error Message.” To add the validator, place your cursor, and then head back in the toolbox. In the “Validation” is the CompareValidator. Double-click the CompareValidator or drag to your page .

Add ControlToCompare and ControlToValidate values

Details should be added. Validator within the open-label, add ControlToCompare = “TextBox1″ and ControlToValidate = “TextBox2. While in there, you probably notice that the defect is not errorMessage described. It would be advisable to switch to something a little easier to use, such as: “The content of the two text boxes are not the same .”

Run Run TestSite example

example and two different types of securities. As soon as focus leaves TextBox2 the CompareValidator errorMessage shown in red. If the values are adjusted to match, once the leaves are TextBox2 the errorMessage disappears.

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Ruby Ruby is a language designed for the definition of class, since it is primarily an object oriented language. Ruby provides a number of shortcuts to create a class that can be followed by those who have some experience with the language .

Create a class in Ruby

Choose a short, descriptive name for their class. The name must be concise enough that anyone reading the code can be a good idea of what the class does not use camel .

for the name of the class. Camel case uses a capital letter at the beginning of the class name and capitalize the first letter of the next word by joining the words. This is instead of using an underscore. For example, the names of Ruby method like this: method_name but class names should look like this: class ClassName .

Create an empty statement: TestClassend

kind of methods for each Plan thing of its kind to be able to do. Write one by one empty methods for each of the methods. A class of microwave, for example, must be able to do things like turn on and put food in it: class Microwavedef put_food_inenddef take_food_outenddef turn_onenddef turn_offendend

Enter the code of methods

Use the variable @ if the syntax of methods to store a variable within an object. The “at” symbol basically said: “This variable is not a local variable is a member variable. It belongs to the object.” You can also use the local variables of the class methods. The example uses the variable @ member of food, the variable that stores what the power is in the microwave: Class Microwavedef put_food_in (food) food foodenddef take_food_outfood = @ = @ @ = nilreturn food food foodenddef turn_onputs “microwave is” enddef turn_offputs “Microwave is off” endend

start with a label “:” and the name of the variable. For example, “food”. Here “food” means “the thing called food.” “@ Food” can not go to attr_ * methods, and pass the value of “@ food”. Since it essentially means “the thing called food can be accessed from outside the class,” “food” should be used .

Put one of three types of methods attr_ * in its class, but outside of the methods. For example, allows attr_reader code outside the class to read the variable, but not write to it. On the other hand, allows attr_writer code outside the class to write to a variable, but not read it. Finally, attr_accessor allows reading and writing .

Put one of three types of methods * attr_ in its class, but outside of any method: Microwaveattr_reader class: fooddef put_food_in (food) = @ food foodend #. .. other methods go here to get brevityend

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If you write articles or blog entries from the Web, it’s likely that you will be forced to learn some basics of HTML programming. Even if you’ve never programmed before, learning the basics of code will help improve their blogs and the like. Here are the most basic steps to create a link .

By far the most common of which probably need to do a blog or article is to create a link. It is very simple. Start with the code of relief to the left. (Click on image to enlarge .)

Under the “URL” section, type the web address or link to the item you want. Utilize the full link, including the “http://” part in the beginning. For example, if I wanted to link to the article you are reading at this time, I wrote: “Make sure http://www.ehow.com/how_2135490_link-simple-html-programming.html ”

to keep the appointment, and replace the URL with the website address .

Then add the text you want to highlight the “<>” part of the code. In the above example, if I wanted to have a link to simply say, “Take a look,” I write the text to the left. (Click to enlarge .)

Leave the rest of the code as it is. Now that you’ve created a link.

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for JavaScript, like all programming languages, with loops and repeated, possibly with the declaration. For JavaScript statement comes in two flavors: a loop on the values, the other entries from more than one subject or set of values .

loop

JavaScript code to the statement, following the syntax below: for (variable = value; condition; increase) (statement (s) }

loop in a range of values by setting a variable equal to the initial value is needed , regarding the status of evidence that the variable does not exceed the maximum, and increasing the variable each time through the loop. In the example below, the numbers between 1 and 9 will be displayed in a series of boxes alert. (i means to increase the value of the variable i by 1.) for (i = 1, i

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An indicator is a variable that contains the memory address of another variable memory. Which was used extensively in the elderly, procedural programming languages like C. Using pointers enables programmers to write very fast, low-level code. However, the leaders also are some security risks that are difficult to identify where the programs are written. Pointer use is permitted in C #, but there are restrictions that must be met. The project must be compiled with the “unsafe” command line argument. In addition, the pointer to appear in a section of code marked with the “unsafe” keyword. This section of the code runs in a “management” state, meaning that runs outside the control of the Common Language Runtime engine .

Create a console application

insecure project start the installation of Visual Studio (see Resources below). Select “New” then “Project” from the File menu in the main window. Expand the “C # Project Type” and highlight “Windows” in the “New Project” dialog box that appears .

Highlight “Console Application”, located in the “Visual Studio installed templates “in” Templates “panel. Click “OK.” This creates the .

Modify your project to allow the use of unsafe code. From the “Main Menu, select” Project “, then choose” (your project name) of properties. ” On the Construction of the tab “Properties” to open the dialog box, select the checkbox for “Allow unsafe code” in the “General”. This will add the “unsafe” command line argument to your project. Close the Properties dialog box .

Look for the “Home” in the “Program.cs” file and notification keys below it. Your code should be written between the keys for opening and closing. It’s OK to make a few blank lines for positioning the cursor after the first key and hit “Enter” several times .

Create a pointer

C # create a dangerous section of code in the newly space created by writing the “unsafe” keyword followed by the opening of a key ripple on the next line and curled a closing brace in line after that. Make some new, blank lines between the brackets by positioning the cursor after the first and pressing “Enter” a couple of times .

Create a pointer in C # in the “dangerous” on its agenda the kind of writing your pointer, an asterisk, and then a space, then the variable name pointer followed by a comma. For example, a pointer in C # called “myIntPointer” to an “int” data type looks like this: int myIntPointer *

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Create a while loop anytime your C program needs to iterate over values or variables. With a few simple precautions, while loops can be easy and powerful .

understand the conditions

Remember that each while loop has a condition that determines when it ends. The loop is repeated until the condition is true. The conditions of participation of the comparisons between variables, such as:

at the same time (T <212) = (increase_heat temperature (temperature );}

Program loop to assess the condition, either beginning or at the end. Evaluate the beginning is the most common case, as in the example above. Evaluate the end ensures that the loop is going to happen at least once:

= do (temperature next_temperature ()) while (temperature <212 );

objective truth: It is vital that the condition to become true, to avoid an endless loop. Make sure that the body of the loop, the inside of keys, which includes changes in the variables involved in conditions, and will ultimately make the condition false .

Accept C capacity to include a provision in a condition that sometimes can make the code shorter and less repetitive. For example:

while ((= temperature next_temperature ()) <212) (update_sensor_logs (temperature );}

breaks the tie

exit. Inside the body of a while loop, you can break the bond immediately, if the condition is false or not. Simply use the break command:

at the same time (T <212) (if (! Sensor_detected ()) break; increase_heat = temperature (temperature );}

Force loop to jump back to the status and re-evaluate what still use the command:

at the same time (T <212) (temperature = next_temperature () if (sensor_error ()) continue; sensor_changes;)

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