number to insert twice

[Chri]

Hi everybody,
I'm sorry, this is the second thread in a few hours, I hope this is a less stupid question than the first...

I'm trying to write a little calculator without any graphic..here's the code

package somma2;

import java.util.Scanner;
import static java.lang.System.out;
import static java.lang.System.in;



public class Somma2 {

   
    public static void main(String[] args) {
     double primoNumero, secondoNumero, terzoNumero, quartoNumero, quintoNumero, somma;   
      
           
   
       out.print("wich operation would you like to do? insert + - * / ");
       Scanner operazione = new Scanner(in);
       
       if (operazione.findInLine(".").charAt(0) == '+') {
           out.println("How many numbers would you like to add? Insert a number from 2 to 5 ");
           Scanner numeriSomma = new Scanner(in);
           
             if (numeriSomma.nextInt() == 1) {
               out.print("You have to insert a number beetwen 2 and 5");
           }
           
             if (numeriSomma.nextInt() == 2) {
               out.print("Insert the numbers here -> ");
             Scanner so2n = new Scanner(in);
             primoNumero = so2n.nextDouble();
             secondoNumero = so2n.nextDouble();
             somma = primoNumero + secondoNumero;
             out.print(primoNumero);
             out.print(" + ");
             out.print(secondoNumero);
             out.print(" = ");
             out.println(somma);
          
           }
           
       }
       

   
                
        
        
    }
}

the problem is: when it asks "How many numbers would you like to add?" if I put 1, no problems, If I put 2, I have to write it two times to make it work! I mean that I have to write "2", then press enter, then insert "2" again, to make it ask the two numbers...

thank you in advance
Chri

[Norm]

A comment on the way the code is written, I recommend that you read the values into a variable and test the content of that variable vs doing it in one step:
if (numeriSomma.nextInt() == 1) {
vs
int nbrIn = numeriSomma.nextInt();
if (nbrIn == 1) {

You are probably having a problem with the Scanner class leaving the newline character in its buffer when you use the nextInt() method.

[Chri]

same...I have to insert it twice

EDIT: now it works! but I can't figure out how...

[Norm]

What did you change?
Did you make the change I recommended: read into a variable?

[Chri]

yes I did what you recommended, i changed if (numeriSomma.nextInt() == 1) { with
nt nbrIn = numeriSomma.nextInt();
if (nbrIn == 1) {

[ftftftftftftftft]

il problema è stato che ogni volta tu metti numeriSomma.nextInt() lui va a leggere un nummero. cio è con numeriSomma.nextInt() == 1 leggi il primo nummero. poi numeriSomma.nextInt() == 2 legge il secondo nummero.

[JosAH]

In English please; English is the lingua franca here.

kind regards,

Jos

[Chri]

il problema è stato che ogni volta tu metti numeriSomma.nextInt() lui va a leggere un nummero. cio è con numeriSomma.nextInt() == 1 leggi il primo nummero. poi numeriSomma.nextInt() == 2 legge il secondo nummero.

Grazie mille :D
but I can't figure out yet why just assigning a variable instead of using directly numeriSomma.nextInt, it works...
OT: you're not Italian right? Anyway, nice! (Hoping you did not use google translate hehe)

for every english speaking people who may have the same problem, here's the answer in english:

the problem was that each time you put numeriSomma.nextInt() it reads a number. so with numeriSomma.nextInt() == 1 it reads the first number. then with numeriSomma.nextInt() == 2 it reads the second number.