Java Scanner class, nothing displayed

Question

I'm new in Java, and i can't figure out why this code doesn't work (no error but nothing displays on the console).

Thanks

import java.util.Scanner;


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


    Scanner sc = new Scanner(System.in);

    String str2 = sc.nextLine();

    System.out.println("Please write something : ");

    System.out.println("You wrote : "+str2);

}

}

`nextLine()` blocks until a new line is available. – Titus Jan 18 '16 at 10:11 — Titus, Jan 18 '16 at 10:11

score 3 · Accepted Answer · answered Jan 18 '16 at 10:12

3

You must enter something and hit enter in order to see any output.

You might want to print the prompt before calling nextLine :

System.out.println("Please write something : ");
String str2 = sc.nextLine();
System.out.println("You wrote : "+str2);

answered Jan 18 '16 at 10:12

Eran

387,369
54
702
768

score 1 · Answer 2 · answered Jan 18 '16 at 10:12

1

Because this piece of code String str2 = sc.nextLine(); expecting the input by main thread. Until you enter something into the console, control won't go to the next line.

answered Jan 18 '16 at 10:12

Raju Guduri

1,237
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score 0 · Answer 3 · answered Jan 18 '16 at 10:16

This is, how you want to implement it:

public class HelloWorld {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);

        System.out.println("Please write something : ");

        String str2 = sc.nextLine();

        System.out.println("You wrote : " + str2);
    }
}

Java Scanner class, nothing displayed

3 Answers3