Topic

StringBuilder

Problem

Concat all strings without digits

Implement a method to concatenate all strings from the given array to a single long string. You must skip all digits inside the input strings.

Use StringBuilder to solve the problem, because the input array can contain a huge number of strings.

Sample Input 1:

T7est i1nput

Sample Output 1:

Testinput

Hint & Explain

Use ".replaceAll("\d","");" method!

Solution

Other solution 1

import java.util.Scanner;

class ConcatenateStringsProblem {

    public static String concatenateStringsWithoutDigits(String[] strings) {
        // write your code with StringBuilder here
        StringBuilder join = new StringBuilder();
        for (String string : strings) {
            join.append(string.replaceAll("\\d", ""));
        }

        return join.toString();
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String[] strings = scanner.nextLine().split("\\s+");
        String result = concatenateStringsWithoutDigits(strings);
        System.out.println(result);
    }
}

Other solution 2

import java.util.Scanner;

class ConcatenateStringsProblem {

    public static String concatenateStringsWithoutDigits(String[] strings) {
        StringBuilder word = new StringBuilder();
        for (String str : strings) {
            word.append(str);
        }
        return String.valueOf(word).replaceAll("\\d", "");
        // write your code with StringBuilder here
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String[] strings = scanner.nextLine().split("\\s+");
        String result = concatenateStringsWithoutDigits(strings);
        System.out.println(result);
    }
}