syntax - Why PHP variables start with a $ sign symbol?

Question

Has anybody ever thought about this question. Why we must write $var_name = value; and not var_name = value;? Yes I know that it is the syntax rule that PHP uses, but why is it a $ sign symbol?

Answer 1

Because PHP was based on Perl which used $, though the symbols Perl used were meaningful and plenty used to indicate the data type, ( such as @ used to indicate an array ) PHP just has $.

PHP in its early stages was a simplistic version of Perl but over time incorporated more of Perl's features, though one may argue PHP was for a long time a simplistic primitive version of Perl since before PHP 5.3 it did not include features that have been around in other languages such as closures/namespacing.

http://en.wikipedia.org/wiki/PHP

Larry Wall, the creator of Perl, was inspired to use $ from shell scripting: http://en.wikipedia.org/wiki/Sigil_%28computer_programming%29