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    <p>Your code suffers a few issues. Here is my code, using a different approach:</p> <pre><code>#!/usr/bin/perl use 5.012; # use strict; use feature 'say'; use warnings; my $number = (int rand 100) + 1; my $max_guesses = 8; GUESS: foreach my $guess_no (1..$max_guesses) { say "($guess_no) Please enter a guess:"; my $guess = &lt;&gt;; chomp $guess; unless ($guess =~ /^\d+$/) { say "Hey, that didn't look like a number!"; redo GUESS; } if ($guess == $number) { say "Congrats, you were on target!"; last GUESS; } elsif ($guess &lt; $number) { say "Nay, your guess was TOO SMALL."; } elsif ($guess &gt; $number) { say "Nay, your guess was TOO BIG."; } else { die "Illegal state"; } if ($guess_no == $max_guesses) { say "However, you have wasted all your guesses. YOU LOOSE."; last GUESS; } } </code></pre> <p>Example usage:</p> <pre><code>$ perl guess-the-number.pl (1) Please enter a guess: 15 Nay, your guess was TOO SMALL. (2) Please enter a guess: 60 Nay, your guess was TOO BIG. (3) Please enter a guess: 45 Nay, your guess was TOO BIG. (4) Please enter a guess: 30 Nay, your guess was TOO SMALL. (5) Please enter a guess: 38 Congrats, you were on target! </code></pre> <p>(all other corner cases (too many guesses, non-numbers as input) work as expected)</p> <p>What did I do differently?</p> <ul> <li>I didn't loop while the guess was too small (← bug!). Instead, I did a loop iteration for each guess. However, a <code>while (1)</code> loop would have worked as well.</li> <li>I did a sanity check on the input, using a simple regular expression. It asserts that the input will be considered numeric by Perl. Else, you get to redo the guess.</li> <li>I initialize all variables as soon as I declare them. This removes any possibilities of uninitialized values popping up in error messages.</li> <li><p>I use proper comparision operators. Perl scalars come in two flavours: stringy and numeric:</p> <pre><code>Stringy Numeric lt &lt; le &lt;= eq == ne != ge &gt;= gt &gt; cmp &lt;=&gt; </code></pre></li> <li>The <code>say</code> function prints the string like <code>print</code>, but appends a newline. This removes akward <code>\n</code>s at the beginning or the end of the string. It makes reading code easier.</li> </ul>
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    1. POUse of uninitialized value $guess in numeric lt (<) line 25 in Perl
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    1. COWould `$guess =~ /^\d+$/` work better to trap non-number input, for this case?
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    2. CO@Kenosis You are right — my previous check assumed no warnings. Fixed it. But now we can't input our guesses in exponential: `5E1` et cetera :(
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    3. COYou're right. Perhaps too much for this program, but could `use Scalar::Util::Numeric qw/isnum/;` and `unless (isnum $guess) { ...`, as it handled your `5E1` well.
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