}
For a complete listing of the special variables, you should see the perlvar
document that comes with your Perl distribution (such as in the perlvar
manual page), or you can go online to http://theoryx5.uwinnipeg.ca/CPAN/perl/pod/perlvar.html.
Operators
Perl supports a number of operators to perform various operations. There are
Comparison Operators
The comparison operators used by Perl are similar to those used by C, awk
, and the csh
shells, and are used to specify and compare values (including strings). Most frequently, a comparison operator is used within an if statement or loop. Perl has comparison opera tors for numbers and strings. Table 25.1 shows the numeric comparison operators and their behavior.
TABLE 25.1 Numeric Comparison Operators in Perl
Operator | Meaning |
---|---|
== | Is equal to |
< | Less than |
> | Greater than |
<= | Less than or equal to |
>= | Greater than or equal to |
!= | Not equal to |
.. | Range of >= first operand to <= second operand |
<=> | Returns -1 if less than, 0 if equal, and 1 if greater than |
Table 25.2 shows the string comparison operators and their behaviors.
TABLE 25.2 String Comparison Operators in Perl
Operator | Meaning |
---|---|
eq | Is equal to |
lt | Less than |
gt | Greater than |
le | Less than or equal to |
ge | Greater than or equal to |
ne | Not equal to |