BEGIN and END Blocks in Perl

You may define any number of code blocks named BEGIN and END in Perl programs, which act as constructors and destructors respectively.

BEGIN { ... }
END { ... }
BEGIN { ... }
END { ... }

Every BEGIN block is executed after the perl script is loaded and compiled but before any other statement is executed.
Every END block is executed just before the perl interpreter exits.
The BEGIN and END blocks are particularly useful when creating Perl modules.

Following example shows its usage −

Example

#!/usr/bin/perl
package Foo;
print "Begin and Block Demo\n";
BEGIN {
   print "This is BEGIN Block\n"
}
END {
   print "This is END Block\n"
}
1;

When above code is executed, it produces the following result −

This is BEGIN Block
Begin and Block Demo
This is END Block

Published on 02-Dec-2019 10:30:49