Needing function help

[stealthy1]

I'm really needing some help please. I notice that the problem I have has been asked by someone else but it still won't work for me. I have one function as below and need to create a new function that drops vowels from a string and uses the isVowel function. I need to use the following plan:-

First declare a local variable called resultString and assign to it an empty string.
Next write code to iterate over the argument string, using a for
loop to access each character of the string in turn.
You will need to use an if statement within the for loop to check
whether the current character is a vowel or not (using the function
isVowel() ). If the current character is not a vowel then add it to
the variable resultString .
Finally, return resultString as the result of your function.

function isVowel(aCharacter)
/************************************************** ******/
/* This function takes one argument, a string which */
/* consists of a single character. The function */
/* returns the Boolean value true if the character 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'))
}
This is what I have so far
function dropVowels(resultString)
/************************************************** *****/
/* 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 removed */
/************************************************** *****/

{
var resultString; //local variable to hold the new string
resultString = '';

for (var resultString = 0; string < resultString.length; string++)
{
if (!isVowel(resultString.charAt(string)))
{
resultString = resultString + 1;
return resultString;
}
}

Sorry this post is so long

[stealthy1]

I forgot to say that I also need to write a program using this function using the following:-

Call the function dropVowels() with the argument 'M150 is a
first level course' and assign the result to a variable called
answer.
Display the string referenced by the variable answer in an alert()
dialogue box.

[Webforumz Staff]

As an Admin for this section I'm going to lay down the following rule regarding homework related questions.

If you need help with your homework, ask only specific questions about your problem. If it's not obvious that you're trying to do it yourself and that you're just stuck with something then you won't get an answer.

For those who want to help. Please put your answers in a way that leads the student to solving the problem on their own, like the syntax for blah is blah or always put a ; on the end of each statement. Please do not write their code for them.

[Webforumz Staff]

The previous reply wasn't specific to you stealthy1, just something general.

So, what problem are you having with your solution?

[stealthy1]

I seem to be having a problem calling the function which makes me think that the code that I have for the function could be wrong. I am new to this and admit to finding it quite hard at times.

[Webforumz Staff]

What kind of error are you getting and how are you trying to call the function?

[stealthy1]

I'm getting just a blank screen. This is what I have got so far

function dropVowels(resultString)
{
var answer;
answer = dropVowels('This is a test');

document.write(answer);
}

[Webforumz Staff]

Well, the function call looks ok. What's your dropVowels function look like?

[stealthy1]

Ok, I have

function dropVowels(resultString)
/************************************************** *****/
/* 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 removed */
/************************************************** *****/

{
var resultString; //local variable to hold the new string
resultString = '';

for (var resultString = 0; string < resultString.length; string++)
{
if (!isVowel(resultString.charAt(string)))
{
resultString = resultString + 1;
return resultString;
}
}

[jamslam]

You have two different functions with the same name.

[stealthy1]

Sorry, being a bit thick here but what do you mean?

[Webforumz Staff]

var resultString; //local variable to hold the new string
resultString = '';
...for your result

and

var resultString = 0;
...for your loop counter

Two different things with the same name so they're overwriting each other.

Aside from that you probably don't want to build up your result string by adding + 1 to it each time a non-vowel is found. Then all you'll get is the number of non-vowels. You probably want to add the currently tested characted to the your resultString instead.

[stealthy1]

Ok, if I try this

function dropVowels(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 removed */
/************************************************** *****/
{
resultString = (''); //local variable to hold the new string

for (var count = 0; count < aString.length; count = count + 1)
{
resultString = aString.charAt(count);
if (!aVowel(aString.charAt(count)))
{
result = result + resultString;
}
}
resultString = result
return resultString;
};

[Webforumz Staff]

This is redundant:

resultString = result
return resultString;

Why not just do?

return result;

And if you define:
resultString = aString.charAt(count);
then you might as well use the variable in the next line:
if (!aVowel(aString.charAt(count)))

But, those are just about writing better code. They shouldn't affect how it works. Does what you wrote work ok?

[jamslam]

You have this code:

Code: Select all

function dropVowels(resultString)
{
var answer;
answer = dropVowels('This is a test');

document.write(answer);
}

And this code:

Code: Select all

function dropVowels(resultString)
/*******************************************************/
/* 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 removed */
/*******************************************************/

{
var resultString; //local variable to hold the new string
resultString = '';

for (var resultString = 0; string < resultString.length; string++)
{
if (!isVowel(resultString.charAt(string))) 
{
resultString = resultString + 1;
return resultString;
}
}

Two different functions with the same name.

I think it might be best if you post your whole code...

[stealthy1]

I have the function isVowel in a function library and need to create a new function called dropVowels and place this in the function library. I then need to call the isVowel function to create an alert box with a string with the vowels missing. I'm very confused!

[jamslam]

You still have two functions with the same name...

And in one of the functions you set the incoming argument to nothing.... so how do you expect to pull vowels for an empty variable?

[stealthy1]

Thanks guys for your help. I have now got it to work much to my delight. Sheer stupidity and simple errors were the problem!

[Webforumz Staff]

It's the simple things that get you.

[benbacardi]

it was the same with the other guy who posted EXACTLY the same problem...