java - Why is my message printing twice when I break out of the inner if? -

i having little problem code. compiling , running works well, however, when attempt break out of inner loop,

system.out.println("type category want add to."); system.out.println("homework, classwork, labs, test, quizzes, midterm, final"); 

the code above printing twice terminal when want print once.

i have feeling simple mistake way brackets aligned having difficulty figuring out how it. appreciated!

import java.util.scanner;  public class getgrade {     public static void main(string[] args) {          scanner input = new scanner(system.in);          final int max = 15;          int[] homework = new int[max];         int[] classwork = new int[max];         int[] lab = new int[max];         int[] test = new int[max];         int[] quizzes = new int[max];         int[] midterm = new int[max];         int[] fin = new int[max];         int hwcount, clcount, labcount, testcount, quizcount, midcount, fincount;         double hwtotal, cltotal, labtotal, testtotal, quiztotal, midtotal, fintotal;         double grade = 0;          string selection = "";          system.out.println();         system.out.println("welcome getgrade!");         system.out.println();          while (true) {              system.out.println("type category want add to.");             system.out.println("homework, classwork, labs, test, quizzes, midterm, final");             selection = input.nextline();              if (selection.equals("homework")) {                  system.out.print("what percentange of grade homework? > ");                 double hwpercent = input.nextdouble();                 system.out.println("now begin typing grades. when finished, type -1.");                  (int = 0; < homework.length; i++) {                     homework[i] = input.nextint();                     hwtotal = homework[i] * hwpercent;                     grade += hwtotal;                     if (homework[i] == -1) break;                 }             }         }     } } 

it's trivial seems:
call input.nextint(); in inner loop not include newline. breaking of innerloop, receiving next line contains newline - character in input.nextline(); remaining input of "-1\n" line , proceed main loop again not match "homework".