Perl in a Nutshell, 2nd Edition

Operators

Table 4-3 lists all the Perl operators from highest to lowest precedence and indicates their associativity.

Table 4-3. Perl associativity and operators, listed by precedence

Associativity	Operators
Left	Terms and list operators (leftward)
Left	-> (method call, dereference)
Nonassociative	++ -- (autoincrement, autodecrement)
Right	** (exponentiation)
Right	! ~ \ and unary + and - (logical not, bit-not, reference, unary plus, unary minus)
Left	=~ !~ (matches, doesn’t match)
Left	* / % x (multiply, divide, modulus, string replicate)
Left	+ - . (addition, subtraction, string concatenation)
Left	<< >> (left bit-shift, right bit-shift)
Nonassociative	Named unary operators and file-test operators
Nonassociative	< > <= >= lt gt le ge (less than, greater than, less than or equal to, greater than or equal to, and their string equivalents)
Nonassociative	== != <=> eq ne cmp (equal to, not equal to, signed comparison, and their string equivalents)
Left	& (bit-and)
Left	| ^ (bit-or, bit-xor)
Left	&& (logical AND)
Left	|| (logical OR)
Nonassociative	.. ... (range)
Right	?: (ternary conditional)
Right	= += -= *= and so on (assignment operators)
Left	, => (comma, arrow comma)
Nonassociative	List operators (rightward)
Right	not (logical not)
Left	and (logical and)
Left	or xor (logical or, xor)

You can clarify your expressions by using parentheses to group any part of an expression. Anything in parentheses will be evaluated as a single unit within a larger expression.

With very few exceptions, Perl operators act ...