无法用Java合并两个句子

Question

I wanted to concat two two strings.

This is my code:

import java.io.*;
import java.util.*;

public class Solution { 

    public static void main(String[] args) {
        int i = 4;
        double d = 4.0;
        String s = "HackerRank ";       
        Scanner scan = new Scanner(System.in);    
        int a; double b;  String c;
        a = scan.nextInt();
        b = scan.nextDouble();
        c = scan.next();
        System.out.println(i + a);
        System.out.println(d + b);
        String res = s.concat(c);
        System.out.println(res);       
        scan.close();
    }
} 

Input:

12
4.0
is the best place to learn and practice coding!

This output:

16
8.0
HackerRank is

Output

I tried everything I can think of.

Answer 1

Edit:

If you change to nextLine() , the previous inputs don't consume the newline character, so you'll have to add in an extra scan.nextLine(); .

See demo online

---

First, declare c (ie String c ), and also a and b (or maybe you did it but forgot to put it in your post?)

But then, your problem is using Scanner::next instead of Scanner::nextLine .

.next() from the docs :

Finds and returns the next complete token from this scanner.

.next() takes the first token, using whitespace as the delimiter, so that's why your output is HackerRank is , assuming your c is holding something like is a great site .

Solution

Change:

c = scan.next(); to c = scan.nextLine();

Answer 2

Here you go..

    public static void main(String[] args) {
        int i = 4;
        double d = 4.0;
        String s = "HackerRank ";
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        double b = scan.nextDouble();
        scan.nextLine();
        String c = scan.nextLine();
        System.out.println(i + a);
        System.out.println(d + b);
        String res = s + c;
        System.out.println(res);
        scan.close();


    }
}

and see below result:

That's because the Scanner.nextInt or nextDouble method does not consume the last newline character of your input, and thus that newline is consumed in the next call to Scanner.nextLine

Answer 3

import java.util.*;
import java.lang.*;
import java.io.*;

class ScannerDemo
{
    public static void main (String[] args) throws java.lang.Exception
    {
        int i = 4;
        double d = 4.0;
        String s = "HackerRank ";
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        double b = scan.nextDouble();
        scan.nextLine();
        String c = scan.nextLine();
        System.out.println(i + a);
        System.out.println(d + b);
        String res = s.concat(c);
        System.out.println(res);
        scan.close();
    }
}

Your Input needs to be

12
4.0
is the best place to learn and practice coding!

Output will be:

16 8.0 HackerRank is the best place to learn and practice coding!

Answer 4

Scan an extra line before scanning the c. Like

scan.nextLine();
c = scan.nextLine();

Because before entering c you press enter, there takes a line input.

Answer 5

int a = scan.nextInt();
double b = scan.nextDouble();
String c = scan.next();

you have to define this variable like I do