Variables start with a $, followed by letter or underscore.
They can contain letters, numbers, underscores, or dashes, but no spaces.
PHP variables are case-sensitive.

The following output was produced with the statement: $var1 = 10; 10

The two variables - $myVariable and $myvariable - are differentThe following line is the variable named $my_variable:
Hello WorldThe following line is the variable named $my_Variable:
Hello World Again
The following output was produced with the statement: $var1 = 100;
100

PHP variables are loosely typed. The can be decared witha simple assingment statement.
This is the numeric variable $var1 after being assinged this string.


However, there is s a distinction between using single and double quotes in the echo command of a variable.
Single quotes will get you the literal output of the string. Double quotes will get you the referential value of the variable.
The following is producted by "echo $var1" and gives the value of the variable $var1.

This is the numeric variable $var1 after being assinged this string.
versus
$var1

Also, it seems that a CHR(12) is automatically append to a variable. The way to eliminate that may be to use the rtrim() function.

This line is a {$var1} of referential integrity.

This line is another Test Test Test of referential integrity.

This line is a third Test Test Test of referential integrity.

There are other variable parameters I may discuss later on.