Beginning Web Development With Perl : From Novice to ... - Nabo

APPENDIX ■ PERL BASICS 315Now we get the right result:$ perl varint4.plThis is the 8th time.$The if StatementIn programming, we often need to test a condition, and if that condition is true, take someaction. This can be performed using an if statement, which has the general syntaxif ( condition ) {statements}Don’t type this in and try to make it run—it is meant to be a general structure of the construct.An important note: those curly braces around the body (the statements) are required. Youmust use them, even if the body is one line of code.For instance, let’s say we want to divide by a number unless that number is 0. We can firstcheck to see if the number is not 0, and if it is not, perform the division.if ($number != 0) {$result = 100 / $number;}Let’s create a program to use the if statement. It will prompt the user to enter a number.If the number is not 0, then 100 is divided by that number and the result is stored in $result. Ifthe number is 0, the result will remain the default value of 0:#!/usr/bin/perl -w# if.pluse strict;print "please enter a number: ";chomp(my $number = );my $result = 0;if ($number != 0) {$result = 100 / $number;}print "the result is: $result\ n";Recall that the statementchomp(my $number = );