function help for a complete newbie

zool_375

Mar 14th 2005, 5:56 am

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:

nullbit

Mar 15th 2005, 9:34 am

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;
}

Body:

var word = 'hello';

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

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

J.D.

Mar 15th 2005, 9:44 am

return ((aCharacter == 'a') || (aCharacter == 'A') ||
(aCharacter == 'e') || (aCharacter == 'E') ||
(aCharacter == 'i') || (aCharacter == 'I') ||
(aCharacter == 'o') || (aCharacter == 'O') ||
(aCharacter == 'u') || (aCharacter == 'U'))
Here's a simpler version:

function isVowel(ch)
{
return new RegExp("[aeiou]", "i").test(ch);
}J.D.