How do I mask out letters that don't match what's expected?

Question

My goal is to create a game of hangman. I wrote code similar to this:

c = []
players_guess = gets
b = "example"
b.scan(/./) {|letter| c << letter}

c.each do |letter|
  if letter == players_guess
    puts letter
  else
    puts "*"
  end
end

The code checks if the player guessed the right letter from the password hidden in variable c, and then displays the password hidden behind the *s and only revealed guessed letters. But when I run the program, the result is always the same, it displays players_guess, and then gives seven *. What is wrong here?

What is wrong is your expectation that something different would happen :) What hint do you need? — Mark Thomas, Dec 19 '12 at 02:10
i expected eg if players_guess = "e" it will display "e*****e". but it gives "e*******". and it displays the players_guess at the beginning like this no matter what letter or number i choose:( — Leo, Dec 19 '12 at 02:15

score 1 · Accepted Answer · edited Dec 19 '12 at 06:18

1

Here's a simple way to do what you want:

word = "example"
puts "Type a letter: "
guess = gets.chomp
puts word.tr("^#{guess}", "*")

This uses the String#tr method to replace all but the guess to *.

The output if you typed e would be e*****e.

edited Dec 19 '12 at 06:18

the Tin Man

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answered Dec 19 '12 at 02:24

Mark Thomas

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score 0 · Answer 2 · answered Dec 19 '12 at 02:15

Your If/Then Logic is Wrong

Your code is as follows:

c.each do |letter|
  if letter == players_guess
    puts letter
  else
    puts "*"
  end
end

The conditional will generally be false, since no single letter is likely to match the entire line retrieved by gets. As a result, you get an asterisk printed for each letter in c.

Some Options to Fix Your Code

You can do a couple of things here.

Just show the string if the strings are equal.

puts players_guess if b == players_guess.chomp

Use a counter in your loop to index into your arrays or strings.
- http://www.ruby-doc.org/core-1.9.3/String.html#method-i-index
- http://www.ruby-doc.org/core-1.9.3/Array.html#method-i-5B-5D
Split both strings into an array, and compare the arrays, printing letters that match or an asterisk on a non-match.
```
c.each_with_index do |char, idx|
  puts char == players_guess.scan(/./)[idx] ? char : '*'
end
```

i don't know the methods you used here, but thanks anyway, i will do my best researching:) — Leo, Dec 19 '12 at 02:21

How do I mask out letters that don't match what's expected?

2 Answers2

Your If/Then Logic is Wrong

Some Options to Fix Your Code