While iterator in Java

Question

I'm experiencing an anomaly in java that i can't wrap my head around.

In my main class i have the following code:

(import java.util.*;)
...

Scanner input = new Scanner(System.in);

String name;
int i = 1;

System.out.println("How many names do you want to enter?");
int iteratorCount = input.nextInt();
iteratorCount++;

  while (i < iteratorCount){
  System.out.println("Ener name number "+i);
  name = input.nextLine();
  System.out.println(name);
  i++;
  }

But during the first itiration of the while loop i don't get asked to write a name. The text "Enter name number 1" does appear however. This is the output:

How many names do you want to enter?
>>5
Ener name number 1

Ener name number 2
>>Jack
Jack
Ener name number 3
>>John
John
Ener name number 4
>>Lisa
Lisa
Ener name number 5
>>Paul
Paul

where >> is user entered text.

Can anyone explain why this is happening?

score 6 · Answer 1 · answered Feb 20 '15 at 14:06

6

Scanner#nextInt doesn't consume the '\n' character (the enter key you hit after you insert an int), scenario:

>>> How many names do you want to enter?
>>> 5 (and hit enter)
>>> Enter name number 
>>> \n (consumed)
>>>

Solutions:

put another nextLine right after nextInt in order to consume that character instead
(not recommended but might help you to understand your problem) have another Scanner instance

answered Feb 20 '15 at 14:06

Maroun

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Hmm, how exactly do you add a second instruction to a scanner object? – Jack Pettersson Feb 20 '15 at 14:26

While iterator in Java

1 Answers1