Using Simple Patterns

To match a pattern (regular expression) against the contents of $_, simply put the pattern between a pair of forward slashes (/), like we do here:

$_ = "yabba dabba doo"; 
if (/abba/) { 
    print "It 

Hash Element Access

To access an element of a hash, use syntax that looks like this:
$hash{$some_key}
This is similar to what we used for array access, but here we use curly braces instead of square brackets around the subscript(key). … Read the rest

Input from Standard Input

chomp($line = <STDIN>); # read the next line and chomp it
Since the line-input operator will return undef when you reach end-of-file, this is handy for dropping out of loops:

while (defined($line = <STDIN>)) { 
    print 

As other languages do, Perl has the ability to make subroutines, which are user-defined functions. The subroutine name comes from a separate namespace, so Perl won’t be confused if you have a subroutine called &fred and a scalar called $fred… Read the rest

A list is an ordered collection of scalars. An array is a variable that contains a list. In Perl, the two terms are often used as if they’re interchangeable. But, to be accurate, the list is the data, and … Read the rest

Numbers

All Numbers Have the Same Format Internally

Internally, Perl computes with double-precision floating- point values. This means that there are no integer values internal to Perl—an integer constant in the program is treated as the equivalent floating-point value. Examples:… Read the rest