这是使用扫描仪扫描多个输入的方法

Question

import java.util.Scanner;
public class servlt {
    public static void main (String args[]){
        Scanner in1 = new Scanner(System.in);
        int t = in1.nextInt();
        int n=0, m=0;
        String input[] = new String[t];
        for ( int i = 0; i<t; i++){
            input[i] = in1.nextLine();
        }
    }
}

there is nothing stored in input[0] . May I know why?

Answer 1

change your code to

int t = in1.nextInt();
in1.nextLine();

it needs to swallow up the linefeed

Answer 2

nextInt() wont consume the \\n (new line), then nextLine will consume \\n character from the number of lines ( left by nextInt ). You can use Integer.parseInt(in1.nextLine()) or and another in1.nextLine() right after you nextInt(), to consume the \\n char.

Trace of your code

    Scanner in1 = new Scanner(System.in);
    int t = in1.nextInt(); // read a number (let say 3)
    int n=0, m=0;
    String input[] = new String[t];
    for ( int i = 0; i<t; i++){
        input[i] = in1.nextLine(); // the first time nextLine will read the \n char
    // The second time an 1 ( for example )
    // And the third time a 2 ( for example )\
    }

    // Finally you will have an array like this
    // input[0] = "\n"
    // input[0] = "1"
    // input[0] = "2"

FIX

  Scanner in1 = new Scanner(System.in);
    int t = Integer.parseInt(in1.nextLine());

    int n=0, m=0;
    String input[] = new String[t];
    for ( int i = 0; i<t; i++){
        input[i] = in1.nextLine();
    }

Answer 3

here is solution, just change input[i] = in1.nextLine(); to input[i] = in1.next(); and it's working, i test it in my locally.

import java.util.Scanner;

public class servlt {

        public static void main (String args[]){
            Scanner in1 = new Scanner(System.in);
            System.out.println("enter total number you want to store:: ");
            int t = in1.nextInt();
            int n=0, m=0;
            String input[] = new String[t];
            for ( int i = 0; i<t; i++){
                System.out.println("enter "+i+"th number :");
                input[i] = in1.next();
            }
            for (int j=0;j<t;j++)
            {
                System.out.println("input["+j+"] value is : "+input[j]);
            }
}
}