Removing vowels from an input string using a loop

Question

I need my output to only be 5 characters long NOT counting the removed vowels. Currently my code is counting the input length and returning that number minus the vowels. This might be confusing. If I input "idontthinkso" it only returns "dnt" instead of what I want it to print out which is "dntth". Btw, I'm not allowed to use Stringbuilder or anything like that, only a loop, so forgive the code. How can I fix this? Here is my code:

import java.util.Scanner;

public class TweetCompressor {
    public static void main(String[] args) {
        Scanner keyboard = new Scanner(System.in);
        String s = "";
        System.out.println("Type a tweet: ");
        String input = keyboard.nextLine();
        int f = 0;
        int tweetLengthAllowed = 5;

        for (int i = 0; i < tweetLengthAllowed; i++) {
            char c = input.charAt(i);
            if (c == 'a' ||
                    c == 'e' ||
                    c == 'i' ||
                    c == 'o' ||
                    c == 'u' ||
                    c == 'A' ||
                    c == 'E' ||
                    c == 'I' ||
                    c == 'O' ||
                    c == 'U') {
                f = 1;
            } else {
                s = s += c;
                f = 0;
            }
        }
        System.out.println(s);
    }
}

Answer 1

public class RemoveVowels {    
    public static void main(String[] args) {

        String inputString = "Java - Object Oriented Programming Language";
        System.out.println(inputString.replaceAll("[aeiouAEIOU]", " "));    
    }    
}

Output:

J v  -  bj ct  r  nt d Pr gr mm ng L ng  g

Answer 2

I'm very much in favor of using a while loop for this, but since you stated you can only use a for loop...

The problem is that your loop will iterate until i = 5, even if a vowel is detected. We need a way to tell the loop to pretend that never happened. You can't decrement i, or you'll be stuck at the same character forever.

Here's what I came up with, I decided to simply increment the tweetLengthAllowed to negate the i increment.

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
    Scanner keyboard = new Scanner(System.in);
    String s = "";
    System.out.println("Type a tweet: ");
    String input = keyboard.nextLine();
    int f = 0;
    int tweetLengthAllowed = 5;
    for(int i = 0; i < tweetLengthAllowed; ++i) { //Must be a for loop
        char c = input.charAt(i);

        if(c == 'a'|| c == 'e'|| c == 'i'|| c == 'o'|| c =='u' || 
            c == 'A' || c == 'E' ||  c == 'I' ||  c == 'O' || c == 'U') {

            f = 1;
            tweetLengthAllowed++; //Allows the loop to continue for one more interation
        } //end if
        else{
            s = s += c;
            f = 0;
        }//end else
    } //end for
    System.out.println(s);

} //end main
} //end class

Also, if you're going to use a big chain of ORs, please do yourself a favor and make it more readable as I did above.

Answer 3

You can do this simpler. Here I iterate every char in the input and break if it reaches the limit:

import java.util.Scanner;

public class TweetCompressor  {

    public static void main(String[] args) {

        Scanner keyboard = new Scanner(System.in);
        String s = "";
        System.out.println("Type a tweet: ");
        String input = keyboard.nextLine();
        int tweetLengthAllowed = 5;
        int i = 0;
        boolean isNotVowel;
        boolean limitReached;

        for (char c : input.toCharArray()) {
            isNotVowel = "AEIOUaeiou".indexOf(c) == -1;
            limitReached = tweetLengthAllowed <= i;

            if (limitReached) { // exit the loop
                break;
            } else if (isNotVowel) { // append the char
                s += c;
                i++;
            }
        }
        System.out.println(s);
    }
}

Run output:

Type a tweet:
idontthinkso
dntth