Information Technology

How to Define variables in PHP

In PHP, a variable starts with the $ sign, followed by

 the name of the variable:

<?php

$Hello = "Hello world!";

$y = 33;

$x = 1.4;

?>

PHP Variables

A variable can have a short name (like x and y)

 or a more descriptive name (age, carname, total_volume).

Rules for PHP variables:

A variable starts with the $ sign, followed by the name of the variable

A variable name must start with a letter or the underscore character

A variable name cannot start with a number

A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ )

Variable names are case-sensitive ($age and $AGE are two different variables)

Remember that PHP variable names are case-sensitive

If you wount to show the output of the example:

you can use "echo" to printing your output look at Next Example:

<?php

$Hello = "Hello world";

$y = 33;

$x = 1.4;

echo $Hello;

echo $y;

echo $x;

?>

The Result is :

Hello world

33

1.4

Note:

It is possible to define() constants with reserved or even invalid names, whose value can (only) be retrieved with constant(). However, doing so is not recommended.

Note:

Case-insensitive constants are stored as lower-case.

Warning

While it is possible to define resource constants, it is not recommended and may cause unpredictable behavior.

Warning

Defining case-insensitive constants is deprecated as of PHP 7.3.0.