Before you can use an array in PHP you have create a variable and declare it as an array. Now there are actually several ways to accomplish this som let me drop an example in right here.

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    //...
    $array1 = array();
    $array2 = array("Allen", "Sanford");
    $array3 = array("firstname" => "Allen", "id" => 423567123);
    $array4[0]['firstname'] = "Allen"; // This is a multi-dimensional array example
    $array4[0]['lastname'] = "Sanford"; // This is a multi-dimensional array example
    $array4[1]['firstname'] = "John"; // This is a multi-dimensional array example
    $array4[1]['lastname'] = "Doe"; // This is a multi-dimensional array example
    //...

And some of you may be asking can you mix and match those, and the answer is yes you can mix and match those examples. Also it is important to note that unlike some languages PHP will allow you to store different data types in a single array. You can also store other arrays in a single array letting you do all the cool multi-dimensional array stuff. Arrays in PHP can have both numeric indexes or string indexes (which are called associative arrays), however they can not be mixed.

Now that you have defined an array you will need to be able to use the information contained in the array(s). For this again you have several options so I will drop another example to show you how you could display the information contained in your array.

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    //...
    // Using the data set form the previous example
    echo $array2[0]; // Allen
    echo $array4[1]['firstname']; // Doe
 
    foreach ($array3 as $key => $value)
        echo $key . " = " . $value . "\n"; // last line will output: id = 423567123
 
     foreach ($array4 as $tempArray)
        echo $tempArray['firstname']; // You should get the picture by now
    //...

This should get you started working with PHP arrays. There are many advanced concepts that I am going to cover in future articles release here on Blogternals. I will be covering Iterators, Hashes, and tree implementations as well as some not so intuitive but useful uses for arrays in PHP.

First style that you will see is in line or single line comments and they can be used two ways.

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    foreach ($rows as $row) // This loops through every row of rows
    {
        // TODO: Implement something cool here
    }

Second style is to use multi-line comments, this is used by the famous phpDocumentor project.

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    /*
        I know that I want to implement this loop later
        but I don't want to run a loop that does nothing
        either so for know I am going to comment out
        all of this.
        Cool!
        foreach ($rows as $row)
        {
            // TODO: Implement something cool here
        }
    */

Third style is the less familiar but oh so useful if stament comment. Allowing you to wrap large blocks of code with an if statement to comment it out.

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    if (0) // This will skip this block of code thereby not executing a loop that does nothing
    {
        foreach ($rows as $row)
        {
            // TODO: Implement something cool here
        }
    } // End if (0)

Inserting PHP code into HTML markup allows us to create interactive, dynamic, pages for our website. In order to achieve this we simply place any HTML markup that is static out side the and ?> , the opening and closing delimiters for PHP code. Also note that we can place multiple PHP code sections in our HTML markup by using different instances of the PHP delimiters.

When the web server receives a request from the web to display our .php file the PHP interpreter will parse all of the code between the delimiters   as PHP code. The PHP interpreter will then return the output of this PHP code to the web server to be inserted into the web page just before it is passed to the requesting browser. The users who are viewing this web page will not be able to see the PHP code, they will only be able to see the resulting output from the PHP code that has been executed on the server.

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
                                   "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <title>PHP Example</title>
    </head>
    <body>
<h1>Example PHP</h1>
 
        <?php echo "Hello World"; ?>
    </body>
</html>

When you get ready to save the PHP files you have created you have to save them with a .php extension, however some text editors do not recognize the .php extension, so you may have to enclose the filename in quotation marks like so, “example.php”. It may be possible that your PHP configuration is configured to parse other file extensions as PHP such as .phtml, .html or .htm, but in any case if your server is configured to parse a certain extension then you are allowed to place PHP code into files with those extensions configured.

Alrighty then , now most tutorials will have you do the classic “Hello World!” as is customary in almost every programming language tutorial in existence, so I shall not disappoint. In your (DOCUMENT ROOT for our purposes we will use http://www.example.com) create a file named hello.php  and place the following in it:

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
                                   "http://www.w3.org/TR/html4/loose.dtd">
<html>
    <head>
        <title>PHP Test</title>
    </head>
    <body>
        <?php echo "Hello World"; ?>
    </body>
</html>

After you copy the above file to your DOCUMENT ROOT you should be able to navigate to http://www.example.com/hello.php and your page should simple display Hello World! If you tried this example and it did not output jus the text “Hello Wolrd!”, it prompted you for a download, or you see the whole file as text, chances are that the server you are on does not have PHP enabled, or is PHP is not properly configured. You should contact your system admin your further help. It you did however get the proper output congratulations you just successfully wrote and executed your first PHP Program.

Now that you have created your first PHP scritp (I should really be calling these scripts as that is what they are) I am going to show you the most useful and shortest PHP script you can write. Ready don’t blink or you’ll miss it. HaHa I know it is written on a web page so how could you miss it you could just re-read it. Anyway here you go. We will call it phpinfo.php

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<?php phpinfo(); ?>

Making a call to the phpinfo() function will show a lot of useful information about your system and setup such as available predefined variables, loaded PHP modules, and configuration settings. I would take a few minutes and familiarize yourself with it and all the information in it.

Well I promised I simple start and I believe I have delivered just that. What do you think? Any suggestions are welcome and all questions will be answered so feel free to ask away leave a comment and get your questions answered.

First we will uncover the simple and most used conditionals, IE specific conditionals.

    <!--[if IE]>
        You are using Internet Explorer or IE as it is called sometimes
    <![endif]-->
 
    <!--[if IE 5]>
        IE Version 5
    <![endif]-->
 
    <!--[if IE 5.0]>
        IE Version 5.0
    <![endif]-->
 
    <!--[if IE 5.5]>
        IE Version 5.5
    <![endif]-->
 
    <!--[if IE 6]>
        IE Version 6
    <![endif]-->
 
    <!--[if IE 7]>
        IE Version 7
    <![endif]-->

Occasionally you may have the need to target non-IE browsers, does not make a whole lot of sense to me but some people may have a need for it. I have even used once or twice by necessity but any way here you go.

    <!--[if !IE]><!-->
        You are NOT using Internet Explorer
    <!--<![endif]-->

Finally for the occasion when you need to target non-IE and a specific IE browser, or any other combination using lte lt or gt gte.

    <!--[if IE 6]><!-->
           Internet Explorer version 6
           OR
    <!--<![endif]-->
 
    You are using
    <!--[if IE 6]>
        IE6 and not
    <!-->
        a non-IE browser
     <!--<![endif]-->