PHP Functions
In this chapter we will show you how to create your own functions.To keep the script from being executed when the page loads, you can put it into a function.
A function will be executed by a call to the function.
You may call a function from anywhere within a page.
Create a PHP Function
A function will be executed by a call to the function.Syntax
| function functionName() { code to be executed; } |
- Give the function a name that reflects what the function does
- The function name can start with a letter or underscore (not a number)
Example
A simple function that writes my name when it is called:| <html> <body> <?php function writeName() { echo "Kai Jim Refsnes"; } echo "My name is "; writeName(); ?> </body> </html> |
| My name is Kai Jim Refsnes |
PHP Functions - Adding parameters
To add more functionality to a function, we can add parameters. A parameter is just like a variable.Parameters are specified after the function name, inside the parentheses.
Example 1
The following example will write different first names, but equal last name:| <html> <body> <?php function writeName($fname) { echo $fname . " Refsnes.<br />"; } echo "My name is "; writeName("Dev Vaghela"); echo "My sister's name is "; writeName("Azaj"); echo "My brother's name is "; writeName("Imran"); ?> </body> </html> |
| My name is Kai Jim Refsnes. My sister's name is Hege Refsnes. My brother's name is Stale Refsnes. |
Example 2
The following function has two parameters:| <html> <body> <?php function writeName($fname,$punctuation) { echo $fname . " Refsnes" . $punctuation . "<br />"; } echo "My name is "; writeName("Dev Vaghela","."); echo "My Frieds's name is "; writeName("Azaj","!"); echo "My brother's name is "; writeName("Imran","?"); ?> </body> </html> |
| My name is Dev Vaghela. My Friend's name is Azaj! My brother's name is Imran? |
PHP Functions - Return values
To let a function return a value, use the return statement.Example
| <html> <body> <?php function add($x,$y) { $total=$x+$y; return $total; } echo "1 + 16 = " . add(1,16); ?> </body> </html> |
1 + 16 = 17
No comments :
Post a Comment