function help for a complete newbie

Discussion in 'JavaScript' started by zool_375, Mar 14, 2005.

0
  1. #1
    Hi,

    I need help with the following, i'm a complete newb so bare with me :) I have written two functions stored in an external library file "library.js" as follows :-

    function isVowel(aCharacter)
    /************************************************************************/
    /* This Function takes one argument, a string which */
    /* consists of a single character. The function */
    /* returns the Boolean true is one of a, A, e, E, i, I, o, O, u or U. */
    /* If the character is not one of these the function returns the Boolean*/
    /* Value false. */
    /************************************************************************/
    {
    return ((aCharacter == 'a') || (aCharacter == 'A') ||
    (aCharacter == 'e') || (aCharacter == 'E') ||
    (aCharacter == 'i') || (aCharacter == 'I') ||
    (aCharacter == 'o') || (aCharacter == 'O') ||
    (aCharacter == 'u') || (aCharacter == 'U'))
    };

    function doubleVowels(aString)
    /*******************************************************/
    /* This function takes a string as its argument and */
    /* returns, as its result, a new string similar to the */
    /* argument except that the vowels have been doubled */
    /*******************************************************/
    {
    resultString = '';

    for (var count = 0; count < aString.length; count = count + 1)
    {
    if (isVowel(aString.charAt(count)))
    {
    resultString = resultString + aString.charAt(count) + aString.charAt(count);
    }
    resultString = aString.charAt(count);
    };

    result = resultString
    return result;
    }

    Basically the first function should look at each char and return true or false i say 'should' as i'm not sure if it works yet :), the second function takes a string and looks at each char (using the first function) to see if it's a vowel, if it is a vowel then it adds it to the string e.g " hello " becomes " heelloo ". the html to make the whole thing work, or not work is as follows :-
    HTML>
    <HEAD>
    <TITLE>vowels
    </TITLE>
    <SCRIPT SRC = "Library.js"> </SCRIPT>
    <SCRIPT >


    var answer;




    doubleVowels('hello'); /*sends string 'hello' to function doublevowels

    answer = doubleVowels(result); /* assigns result of function to variable

    window.alert(+ answer); /* displays result in alert box


    </SCRIPT>
    </HEAD>
    <BODY>
    </BODY>
    </HTML

    At the moment NAN is returned in the alert box. This is a really simple problem, but I am tearing my hair out trying to get it to work, I know i'm 99% there, please help before I have no Hair left.... :confused:
     
    zool_375, Mar 14, 2005 IP
  2. nullbit

    nullbit Peon

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    #2
    I made a few revisions, it should work.


    Head:
    
function isVowel(aCharacter)
{
  return ((aCharacter == 'a') ||
          (aCharacter == 'A') ||
          (aCharacter == 'e') ||
          (aCharacter == 'E') ||
          (aCharacter == 'i') ||
          (aCharacter == 'I') ||
          (aCharacter == 'o') ||
          (aCharacter == 'O') ||
          (aCharacter == 'u') || 
          (aCharacter == 'U'))
}

function doubleVowels(aString)
{
  var resultString = '';

  for(var count = 0; count < aString.length; count ++)
  {
    if(isVowel(aString.charAt(count)))
      resultString += aString.charAt(count) + aString.charAt(count);
    else
      resultString += aString.charAt(count);
  }

  return resultString;
}
    Code (markup):
    Body:
    
var word = 'hello';

var answer = doubleVowels(word); /* assigns result of function to variable */

window.alert(answer); /* displays result in alert box */
    Code (markup):
     
    nullbit, Mar 15, 2005 IP
  3. J.D.

    J.D. Peon

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    #3
    Here's a simpler version:

    function isVowel(ch)
{
    return new RegExp("[aeiou]", "i").test(ch);
}
    Code (markup):
    J.D.
     
    J.D., Mar 15, 2005 IP