Proper way to define variables.
<?php
$var = 'Hello World';
$_var1 = 100;
$_12var = 'India';
$Var = 'Welcome to this tutorial';
?>
Program to check local and global variables.
<?php
$var1 = 12;
$var2 = 22;
$var3 = 0;
function getdata(){
global $var1, $var2;
$var3 = $var1 + $var2;
echo $var3;
}
getdata();
?>
Reference variable example
<?php
$var = 'Hello';
$$var = 'Welcome';
echo $Hello;
?>
Program to get type of variable
<?php
$var = 'Hello World';
$_var1 = 100;
$_12var = 'India';
$var2 = 10.883;
echo gettype($var);
echo '<br/>';
echo gettype($_var1);
echo '<br/>';
echo gettype($_12var);
echo '<br/>';
echo gettype($var2);
?>