Monday, 20 June 2016

java - Why nextLine is being skipped when using do while loop

I have to write a program for my class that takes user input for homework,labs,tests,etc,puts them in a string, and there is a separate class that splits them in separate "double"numbers and contains a writeToFile method to write the student's grade into a file.



I keep getting a problem though.. When I ask the user for their name the first time, it works fine, but if the user decides to enter the do-while loop again, the "What is your name" is skipped and it goes straight to id. I know it has something to do with the last input not being a string, and the solution to that is to put a "keyboard.nextLine();" above the question, but I tried that and it just asks the user for their name before the question is even asked..



import java.util.Scanner; 

import java.io.*;
import java.text.DecimalFormat;

public class GradeApplication
{
public static void main(String[] args) throws IOException
{
Scanner keyboard = new Scanner(System.in);

//Define variables

String name;
int id;
String homework;
String labs;
String tests;
double project;
double discussion;
int answer;

do

{
System.out.print("\nWhat is your name? ");
name=keyboard.nextLine();

System.out.print("\nWhat is your student ID? ");
id=keyboard.nextInt();

homework = keyboard.nextLine();
System.out.println("\nPlease enter homework grades separated by spaces:");
homework = keyboard.nextLine();


System.out.println("Please enter lab grades separated by spaces:");
labs = keyboard.nextLine();

System.out.println("Please enter test grades separated by spaces:");
tests = keyboard.nextLine();

System.out.println("Please enter project grade:");
project = keyboard.nextDouble();


System.out.println("Please enter discussion grade:");
discussion = keyboard.nextDouble();

System.out.println("\nResults: ");
//Call toString method
Student_Khazma s = new Student_Khazma(name,id,homework,labs,tests,project,discussion);
System.out.print(s.toString());

//Open file
PrintWriter outputFile= new PrintWriter("gradeReport.txt");

System.out.println(s.writeToFile());
outputFile.close();

System.out.print("\n\nWould you like to see your grade report again? (1 is yes, 2 is no): ");
answer=keyboard.nextInt();

System.out.print("\n\nWould you like to see your grade report again? (1 is yes, 2 is no): ");
answer=keyboard.nextInt();

}while(answer==1);


}
}

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