How to properly replace characters in a string in JavaScript using the for loop, based on user input?

Question

func = function() {
  val = document.getElementById('word').value;
  first = val.charAt(0).toUpperCase();
  rest = val.substring(1).toLowerCase();
  valConvert = first + rest;
  undersc = '_';
  fullUndersc = '';
  for (var i = 2; i < val.length; i++) {
    fullUndersc = fullUndersc + undersc;
  }
  wordToGuess = valConvert.charAt(0) + fullUndersc + valConvert.slice(-1);
  document.getElementById('form').innerHTML = wordToGuess;
  document.getElementById('letterIn').style.display = 'block';
  guess = function() {
  var charac = document.getElementById('letter').value;
    for (var i = 1; i < val.length -1; i++) {
      if (charac == valConvert.charAt(i)) {
        wordToGuess = wordToGuess.replace(new RegExp(wordToGuess.charAt(i), 'i'), charac);
        document.getElementById('form').innerHTML = wordToGuess;
      }
    }
  }
}

The outer function takes user's input, converts letters to a proper case (upper case and lower case), leaves first and last letter as it is and swaps the rest of characters with _. The inner function (guess) again takes user's input (just one character) and checks whether or not the character exists in user's previous input. This function works but I want it to replace _ with the input letter IN THE PROPER POSITION.

In short - I am trying to make The Hangman game.

Any help will be much appreciated.

<!--HTML
<form onSubmit="func(); return false" id="form">
    Type in a word below<br /><input class="" id="word" type="text" autofocus />
  </form>

<form onSubmit="guess(); return false" id="letterIn">
Enter a letter: <input class="" id="letter" type="text" size="1" maxlength="1" autofocus />

</form>
-->

I just see a bunch of text. That either means it's bedtime for me or your question isn't very clear. — Jonathan
– Jonathan, Commented Feb 4, 2014 at 22:59
I'm new to JavaScript and probably my question isn't clear enough. I can't figure out how to create a function that will swap _ signs in the right position, with a character input by user. I will add the HTML code now so that it will be easier to find out what I mean. — rydwan
– rydwan, Commented Feb 4, 2014 at 23:35
People on SO often provide a jsFiddle to make it easier for others to help them. — Jonathan
– Jonathan, Commented Feb 4, 2014 at 23:40

reergymerej · Accepted Answer · 2014-02-05 03:20:53Z

1

You'll need to keep track of the original phrase as well as the clues.

var phrase = 'A phrase to guess',
  clue = '_ _____ __ _____';

function updateClue (guess) {
  // split the clue into an array
  clue = clue.split('');

  // loop through the characters in the phrase
  for (var i = 0; i < phrase.length; i++) {

    // if the letter in the phrase matches the guess
    if (phrase.charAt(i).toLowerCase() === guess.toLowerCase()) {

      // replace the corresponding character in the clue
      clue[i] = phrase.charAt(i);
    }
  }

  // convert the clue array back into a string
  clue = clue.join('');
  return clue;
}

Here's silly (working) example.

edited Feb 5, 2014 at 3:20

answered Feb 4, 2014 at 23:58

reergymerej

2,4172 gold badges27 silver badges32 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

rydwan Over a year ago

Thanks very much blurd. I didn't realise it was so simple! That's what I was looking for. Thanks again!

reergymerej Over a year ago

You'll need to do some validation and whatnot, but this is the basic idea. Feel free to accept this answer. ;)

rydwan Over a year ago

OK blurd, I totally accept your answer, however cannot vote at the moment (need to have 15 points of reputation). I appreciate that.

Collectives™ on Stack Overflow

How to properly replace characters in a string in JavaScript using the for loop, based on user input?

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related