A.10 Operator Precedence
Operator
precedence determines the order in which
the operations are applied. For instance, in Perl, the expression: 3 + 3 * 4
isn't evaluated left to right, which calculates 3 +
3 equals 6, and 6 times 4 results in a value of 24; the precedence
rules cause the multiplication to be applied first, for a final
result of 15. The precedence rules are available in the
perlop manpage and in most Perl books. However, I
recommend you use parentheses to make your code more readable and to
avoid bugs. They make the following expressions unambiguous; the
first: (3 + 3) * 4
evaluates to 24, and the second: 3 + (3 * 4)
evaluates to 15. |