Character and String input in Java

Question

I am new to Java and wrote a program for basic I/O operations of different data types. I want the program to input 1 a abcd and output them in in three different lines respectively. But when I input 1 a the program terminates and outputs 1 , a and an empty line in three different lines. I am not able to take a character input properly, which I think is the root of the problem. Can someone please guide me as to where I got it wrong ?

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.Scanner;
import java.util.StringTokenizer;

public class Main {
    static class FastReader {
        BufferedReader br;
        StringTokenizer st;

        public FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException  e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        char nextChar() {
            char c = ' ';
            try {
                c = (char)br.read();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return c;
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }

    public static void main(String[] args) {
        FastReader in = new FastReader();
        PrintWriter out = new PrintWriter(System.out);
       int n = in.nextInt();
        char c = in.nextChar();
        String s = in.nextLine();
        out.println(n);
        out.println(c);
        out.println(s);
        out.close();
    }
}

See https://stackoverflow.com/questions/13102045/scanner-is-skipping-nextline-after-using-next-or-nextfoo — Federico klez Culloca, Oct 22 '20 at 07:57

Hasindu Dahanayake · Accepted Answer · 2020-10-22T08:19:48.143

0

Refactor the code like below.

char c = in.nextChar();//Keep this line as same
in.nextLine();//(only add this line after the above line)Place this line otherwise your String abcd can't insert

output:

1
a
abcd

edited Oct 22 '20 at 08:19

answered Oct 22 '20 at 08:11

Hasindu Dahanayake

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score 0 · Answer 2 · answered Oct 22 '20 at 08:17

you mean like follow:

input: 1 a abcd
out:
1
a
abcd

you reference this code:

    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        String inputLine = bufferedReader.readLine();
        if (inputLine!=null && inputLine.length()>0) {
            String[] splitInputLine = inputLine.split("\\ ");
            for (String outLine : splitInputLine) {
                System.out.println(outLine);
            }
        }
        bufferedReader.close();
    }

No I want to use the variables further. I was just trying to figure out how to take the input output properly first. — jadhavvv, Oct 22 '20 at 08:26

Character and String input in Java

2 Answers2