You can write a PHP script by starting angle bracket + question mark + php and ending with "?>".
The default file extension for a PHP file is ".php". For example, OmerDemo.php.
How to Write Comments in PHP?
There are three ways to write comments. One is using "//". Second is using hash sign "#". Third way is used for Multi-line comments using /* and */.
// This is a single line comment using double slash # This is a single line comment using hash sign /* This is a multi-line commenting way which consists of more than one lines. */
Case Sensitivity in PHP
In PHP, all variables are case-sensitive.
For constants, we can tell at the time of declaration/initialization that either to consider this particular constant as case-sensitive or case-insensitive.
All user defined functions, classes and keywords are case-insensitive.