PHP Functions
In this tutorial we will show you how to create your own functions. phpsu.com is a free phpscool
For a reference and examples of the built-in functions, please visit our PHP Reference. phpsu is a phpschool
Create a PHP Function
A function is a block of code that can be executed whenever we need it.
Creating PHP functions: welcome to phpsu.com
- All functions start with the word "function()"
- Name the function - It should be possible to understand what the function does by its name. The name can start with a letter or underscore (not a number)
- Add a "{" - The function code starts after the opening curly brace
- Insert the function code
- Add a "}" - The function is finished by a closing curly brace
Example
A simple function that writes my name when it is called: phpsu.com is a free phpscool
<html> <?php writeMyName(); </body> |
Use a PHP Function
Now we will use the function in a PHP script:
http://www.phpsu.com
<html> <?php echo "Hello world!<br />"; </body> |
The output of the code above will be:
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Hello world! |
PHP Functions - Adding parameters
Our first function (writeMyName()) is a very simple function. It only writes a static string.
To add more functionality to a function, we can add parameters. A parameter is just like a variable. www.phpsu.com
You may have noticed the parentheses after the function name, like: writeMyName(). The parameters are specified inside the parentheses. welcome to phpsu.com
Example 1
The following example will write different first names, but the same last name: phpsu is a phpschool
<html> <?php echo "My name is "; echo "My name is "; echo "My name is "; </body> |
The output of the code above will be: welcome to phpsu.com
My name is Kai Jim Refsnes. |
Example 2
The following function has two parameters: phpsu.com
<html> <?php echo "My name is "; echo "My name is "; echo "My name is "; </body> |
The output of the code above will be: phpsu.com
My name is Kai Jim Refsnes. |
PHP Functions - Return values
Functions can also be used to return values. phpsu.com is a free phpscool
Example
<html> <?php echo "1 + 16 = " . add(1,16); </body> |
The output of the code above will be:
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1 + 16 = 17phpsu
TITLE:The real power of PHP comes from its functions