The real power of PHP comes from its functions; it has more than 1000 built-in functions.
PHP User Defined Functions
Besides the built-in PHP functions, we can create our own functions.
A function is a block of statements that can be used repeatedly in a program.
A function will not execute immediately when a page loads.
A function will be executed by a call to the function.
Create a User Defined Function in PHP
A user defined function declaration starts with the word “function”:
Syntax
function functionName() {
code to be executed;
}
Note: A function name can start with a letter or underscore (not a number).
Tip: Give the function a name that reflects what the function does!
Note Function names are NOT case-sensitive.
In the example below, we create a function named “writeMsg()”. The opening curly brace ( { ) indicates the beginning of the function code and the closing curly brace ( } ) indicates the end of the function. The function outputs “Hello world!”. To call the function, just write its name:
Example
<?php
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function writeMsg() { |
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echo "Hello world!"; |
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}
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writeMsg(); // call the function |
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?>
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