When coding, it is always important to write comments that explain your code. Comments make your code easier to read and understand.
Most coding languages have a specific syntax that accommodates both line and block comments.
Let’s take a closer look at how comments and simple statements work in Perl.
Statements are instructions for the compiler. They perform operations on variables during run-time.
All statements must end with a semi-colon (
;) in Perl. This aspect of programming in Perl is similar to C/C++ or Java.
Statements in Perl can be single-line or multi-line. Multi-line statements are handy when writing an expression that is too long for one line.
Let’s write a few statements that perform basic arithmetic operations:
$v = 4; $w = 7; $x = 10; $y = 2; $z = $w + $y * $x - $v;
Comments are parts of your code that the compiler ignores during compile-time. They merely serve the purpose of conveying information to the reader.
Like statements, comments in Perl can also be single line and multi-line. Multi-line comments are often referred to as ‘block comments.’
Single line comments start with the
## This is a single-line comment
Block comments in Perl are enclosed within the
=cut symbols. Everything written after the
= symbol is considered part of the comment until
=cut is encountered.
There should be no whitespace following
=in the multi-line comment.
=This is a block comment =cut
We will now write a simple program in Perl that shows how to write comments and simple statements.
=This program will display 'Hello World' on the screen =cut $string = "Hello World"; # A simple assignment statement print $string;
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