Operators

时间：2008-01-17 来源：xiaoaizhen

**		Exponentiation
+ -	* /	Addition, subtraction, multiplication, division
%		Modulo division
& \|	^	Bitwise AND, bitwise OR, bitwise exclusive OR
>>	<<	Bitwise shift right, bitwise shift left
\|\|	&&	Logical OR, logical AND
.		Concatenation of two strings
x		Returns a string or array consisting of the left operand (an array or a string) repeated the number of times specified by the right operand
All of the above operators also have an assignment operator, e.g., .=
->		Dereference operator
\		Reference (unary)
!	~	Negation (unary), bitwise complement (unary)
++	--	Auto-increment (magical on strings), auto-decrement
==	!=	Numeric equality, inequality
eq	ne	String equality, inequality
<	>	Numeric less than, greater than
lt	gt	String less than, greater than
<=	>=	Numeric less (greater) than or equal to
le	ge	String less (greater) than or equal to
<=>	cmp	Numeric (string) compare. Returns -1, 0, 1.
=~	!~	Search pattern, substitution, or translation (negated)
..		Range (scalar context) or enumeration (array context)
?:		Alternation (if-then-else) operator
,		Comma operator, also list element separator. You can also use =>.
not		Low-precedence negation
and		Low-precedence AND
or	xor	Low-precedence OR, exclusive OR

All Perl functions can be used as list operators, in which case they have very high or very low precedence, depending on whether you look at the left or the right side of the operator. Only the operators not, and, or and xor have lower precedence.

A "list" is a list of expressions, variables, or lists. An array variable or an array slice may always be used instead of a list.

Parentheses can be added around the parameter lists to avoid precedence problems.