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PHP Lesson 3 – Creating Functions

admin — Mon, 02 May 2005 00:22:11 +0000

How to create Functions in PHP and also how to Pass Variables to Functions. Introduction: You will need to have a PHP web server for this tutorial. We recommend SimpleHost.com for only $7.50 with Unlimited Disk Space, Subdomains, and Emails Accounts. PHP has hundreds of predefined functions (maybe thousands). This tutorial gives examples on how to create your own php functions. There are two rules I would like to share with you before we start. Rule 1: Make sure your new function name does not exhist. You can check PHP.net for a complete list of PHP predefined functions. Rule 2: Do not declare/define the same function more than once inside the same file. You will get an error. OK, let's create our first function. This function will display a text advertisement. We will call this function ads().

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Now you can display the same ad however many times you want just by calling the function ads().

Passing Values to Functions:

Let's say we want to randomly display three ads. We could do this by placing three text ads inside our ads() function and then passing a random value to it, to indicate which ad to display. We can do this by using a parameter variable inside the function. For example $n will be the variable and this is how it is placed inside our ads function like so "ads($n)". This variable holds a copy of the value passed to it. Now we need to set $n to a random number between 1 and 3. We can do this by using one of PHP pre-defined functions called rand(). If you want a random number between 1 and 3 (inclusive), for example, use "rand (1, 3)". To make this a little more clear, view the code below:

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// first define the function function ads($n) { $a = "http://newsourcemedia.com"; if($n == 1) echo "Visit NewSourceMedia.com for free tutorials"; if($n == 2) echo "NewSourceMedia.com for PHP and much more!"; if($n == 3) echo "PHP is Number One!" } // end of function

// define the random value for $n $n = rand (1, 3); // now call the function ads() with the value $n ads($n); ?>

PHP strip remove white space from end of string

admin — Sat, 27 Mar 2004 00:22:11 +0000

Need to remove the white space at the end of a string before recording the data. Use PHP's rtrim(). rtrim(): rtrim is great for deleting that unwanted space at then end of strings. The perfect example for using this function is when receiving data from an online form and, at the end of a data field, some one leaves an extra white space. This white space means nothing and you want to delete it. rtrim() to the rescue. Example:

Other Examples: You can also trim down a string by matching words or letters and the end of a string. Example:

// Example 1: Character-by-character comparison match.

echo rtrim('This is a test test code', 'test code');
// returns 'This is a'

// Example 2: matches the last whole word with half the letters

echo rtrim('This is a test', 'est');
// returns 'This is a'
?>

Array: Lesson Part 1

admin — Sat, 28 Feb 2004 00:22:11 +0000

Learn PHP arrays and how easy it is to store and organize complex data structures.

Introduction:

You may already know about PHP variables, and how unfortunately you can only store only one value at a time. But now lets move on to a new type of variable called an array. Arrays allow you to store as many values as you want inside it. It keeps track of the information by indexing the data by a number or a string. Think of a variable as a bottle of soda. And think of an array as a case of sodas, or a warehouse of sodas. Elements in an Array Example: Values: (“Bart”, “Sharon”, “Betty”) Index Number: (0, 1, 2) Which Element? (First, Second, Third) The index always starts as zero. This easy to forget, so if you did not get what you expected when outputting a value in an array, the chances are that you started counting at one instead of zero. Creating Arrays Use the Array() Function: $states = array (“NY”, “PA”, “CA”) You can now access the second element by the index “1”: echo “$state”; This will display as “PA”. Creating or Adding to Arrays with Array Identifier:

$states = “NY”; $states = “PA”; $states = “CA”; The values will be listed in the same line order as to when they where set. You can also place them in the order you want by using the index number placed inside the square brackets like so:

$states = “PA”; $states = “CA”; $states = “NY”; When using the identifier with an index number to set the value, be sure never to set the index number too high. For example, if there are only 3 elements in an array and you want to add a new value to the end of the array, you must use the index number . The safe way to achieve this would be not to use an index number and just leave the square brackets blank like so:

$state = array(“NY”, “PA”, “CA”); // add a new state to the end of the our array of states $state = “OH”; Conclusion: This is just Part 1 of PHP Array Tutorials for developing your on web programs. Be sure to read our Part 2 "Complex Data Arrays" to help you master arrays and create more dynamic web applications.

Source Include

admin — Sat, 28 Feb 2004 00:22:11 +0000

Learn how to save time and money by using the javascript src() function to including local or remote document like headers, footers, css, images, and flash files. Introduction: With Javascript, you can save time and money by using the ("src") to include remote or local documents. For example, you may have a web site serving 20 web pages. All 20 pages display the same header and footer item like site name, logos and links. However, if you were to change the header text, you would have to apply those changes all 20 pages manualy. That's not fun. Here is a faster way (View the test page.) Source Code of included header file (JS-IncludeB.js): Source Code of included footer file (JS-IncludeB.js): Source Code of main page: