☛ Here are the most important things to know about variables in PHP.

☛ All variables in PHP are denoted with a leading dollar sign ($).

☛ The value of a variable is the value of its most recent assignment.

☛ Variables are assigned with the = operator, with the variable on the left-hand side and the expression to be evaluated on the right.

☛ Variables can, but do not need, to be declared before assignment.

☛ Variables in PHP do not have intrinsic types - a variable does not know in advance whether it will be used to store a number or a string of characters.

☛ Variables used before they are assigned have default values.

☛ PHP does a good job of automatically converting types from one to another when necessary.

☛ PHP variables are Perl-like.