PHP Functions
PHP functions are used to reuse piece of code many times. There are various built-in functions in PHP. A function will be executed by a call to the function.
Following are the advantage of PHP function.
- Code Reusability
- Less Code
- Easy to understand
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
functionabc(){
echo "Created User define function !";
}
abc(); // calling a function
?>
</body>
</html>
Output
Created User define function !
PHP function with Arguments
In PHP function, we can pass the information through arguments by comma. It supports Call by value, Call by Reference, Default argument values and variable –length argument list.
Example 1
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
function name($nm){
echo "Your Name is:"."$nm"."<br>";
}
name('Alok'); // calling function With single argument
name('John'); // calling function with single argument
?>
</body>
</html>
Output
Alok
John
Example2
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
function name($nm,$age){
echo "Your name:"."$nm"." "."Age"."$age"."<br>";
}
name("Alok","20"); // calling function With two argument
name('John',"30"); // calling function with two argument
?>
</body>
</html>
Output
Your name:Alok Age20
Your name:John Age30
PHP Call By Reference
In PHPcall by reference, the function does not modify the actual value by default. But if we want to pass the value as a reference then it is possiblethrough ampersand ( &) symbol.
Example:
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
function adder(&$val)
{
$val .= 'Call By Reference';
}
$nm= 'Hello ';
adder($nm);
echo $nm;
?>
</body>
</html>
Output
Hello Call By Reference
PHP Call By Value
Call by value is used to pass the value directly to a function. The called function uses the value in a local variable. There is no affect the source variable when change it.
Example:
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
//Call by value program
functionabc($x){
$x=$x+30;
return($x);
}
$a=40;
echoabc($a)."<br>";
echo ($a);
?>
</body>
</html>
Output
70
40
PHP Default Argument Value Function
Sometime we do not want to pass any value to the function then it will use default arguments in function.
Example
<!DOCTYPE html>
<html>
<head>
<title>PHP Tutorial</title>
</head>
<body>
<?php
function fun($name="Ram"){
echo "Hello $name<br/>";
}
fun("John");
fun();//passing no value
fun("Rohan");
?>
</body>
</html>
Output
Hello John
Hello Ram
Hello Rohan