Help with a recursion method

[milk242]

Hi everyone,

I'm trying to write a recursive method that removes vowels from a string. If someone can help me formulate a pseudocode to do this, that would be great.

So far my code is:

public static void RemoveVowels(String str)
     if str.substring(0,1).compareToIgnoreCase("a" == 0)
     {
          str.replace("a", "");
          RemoveVowels(s.substring(1));
     }
     else
          RemoveVowels(s.substring(1));
 

My reasoning is that if the character at beginning of string is not "a" then it'll execute the else statement and make the sentence one character shorter. Once it reaches an "a", it'll remove it and make the string one letter shorter.

I'm also having trouble of coming up with a way to return this new string. Should I use a return statement?

Thanks!

[dmjpro]

Why do you need to use Recursive Call?
Use regular expression to replace all the vowels with empty String ;)

return your_string.replaceAll("[aeiou]","");
 

You can also alternate the code, if you don't understand Regular Expression.

your_string = your_string.replaceAll("a","");
your_string  = your_string.replaceAll("e","");
.....
...
return your_string.replaceAll("u","");
 

[milk242]

Thanks for the help, but I'm learning from a book and would like to figure out this recursion method. I know it would be easier to use iterative method or even regular expression.

[dmjpro]

Ok that's fine...
What you want to learn ? Recursive Method?
Then take another example to learn it ..Suppose calculate the factorial or have Google with "recursive examples+java" ;)

[JosAH]

Split up your recursive problem:

1) if your string is empty there's nothing to remove.
2) remove vowels from the string yourString.substring(1);
3) if the first character is a vowel return the string returned by step 2)
4) otherwise return the first character plus the string returned by step 2)

kind regards,

Jos

[milk242]

Thanks JosAH,

That really helped a lot!

And thanks to everyone else!