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

Answer 1

This has been common in computer languages for a long time, that's all. Long before Perl, too! For instance, check out Commodore 64 BASIC

10 PRINT "WHAT IS YOUR NAME?"
20 INPUT A$
30 IF A$="BAHKTIYOR" THEN PRINT "HEY CHECK OUT THAT DOLLAR SIGN"

In BASIC the $ was after the variable name, however.