从stdin读取多字符串

Question

I want to read multiple words into a string called input . The words can be casted into numeric values like "1 14 5 9 13" . After the user input, the string will be converted into a string array separated by spaces.

public class ArraySum {

  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
    int n = Integer.parseInt(scanner.next());
    System.out.println("Please enter "+n+" numbers");
    String input = scanner.next(); // ERROR: only the first word is read
    String[] inputs  = input.split("\\s+"); 
    int sum=0;
    for (int i =0; i<inputs.length; i++){
        if (!inputs[i].equals(""))
            sum+= Long.parseLong(inputs[i]);
    }
    System.out.print(sum);
}
}

However only the first word is read into the string.

This answer suggests using nextLine() to read a multi-word string, but if I change it, an error was thrown.

java.lang.NumberFormatException: null

Apparently an empty/null string was inputted before I entered any word.

Answer 1

You have to use nextLine after nextInt to clear your Scanner like this :

int n = scanner.nextInt();//read your int
scanner.nextLine();//clear your Scanner
System.out.println("Please enter " + n + " numbers");
String input = scanner.nextLine();//read your String example 12 55 66