I'm trying to read separate names and instruments up until the total number of bandmembers(asked earlier in the program) is reached. The program reads the amount, and reads the first name. However after that it fails in that it only reads the first name, it does not print any name or instrument after.
The while loop below is the most likely source of the problem:
i = counter
while(i <= bandMembers)
{
System.out.println("What is band member " + i + "'s name?");
kb.nextLine();
String bName = kb.nextLine();
System.out.println("What instrument does " + bName + " play?");
kb.nextLine();
String bNamePlay = kb1.nextLine();
list = list + i + ":" + " " + bName + " - " + bNamePlay+ "\n";
i++;
}
This is what it prints if I entered the first name as bName1:
Band Members
--------------
1: bName1 -
2: -
3: -
Any help appreciated, thanks.
Use BufferedReader instead.This will fix your problem.:-
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
i=counter;
while(i<=bandMembers){
System.out.println("Enter band member "+i+" name:-");
String bName=br.readLine();
System.out.println("What instrument does "+bName+" play?");
String bNamePlay=br.readLine();
list = list + i + ":" + " " + bName + " - " + bNamePlay+ "\n";
i++;
}
You should be using
String bName = kb.next();
Under the assumption that you are using a Scanner.
When you call nextLine() it reads the remainder of the same line and does not wait for input.
I don't have enough rep to comment on the issue you're having:
I was using kb.next at first but it read each word separated by a space as the next name. For example I would input "Jimmy loose hands" and it would prompt for Jimmy's instrument correctly, but it would then ask for band member 2's name and "what instrument does loose play?" simultaneously. So it took the second word as the next name.
What you may want to do is remove the "kb.nextLine();" before "String bName = kb.nextLine();"
I don't have an IDE open to confirm it, but that may be the reason that it is taking the second word/string entered as the name.
Related
I have the following code:
String f_name = "";
System.out.println(ANSI_PURPLE + "What is your first name?");
System.out.print(ANSI_RESET + " Type your name here (use only latin characters) > ");
while(!sc.hasNext("[A-Za-z]*")) {
System.out.println(ANSI_RED + " ERROR: Invalid option! ");
System.out.print(ANSI_RESET + " Type your name here (use only latin characters) > ");
f_name = sc.next().toUpperCase();
}
System.out.println("First Name = " + f_name);
The issue with the above code is that it would store what has previously added.
for example:
What is your first name?
Type your name here (use only latin characters) > 123
ERROR: Invalid option!
Type your name here (use only latin characters) > c
First Name = 123
How to fix so that the validation of latin characters will still work, redirect the user to same question if there is a mistake and store the correct value?
CORRECT ANSWER TO MY QUESTION:
...
while(!sc.hasNext("[A-Za-z]*")) {
System.out.println(ANSI_RED + " ERROR: Invalid option! ");
System.out.print(ANSI_RESET + " Type your name here (use only latin characters) > ");
sc.next();
}
f_name = sc.next().toUpperCase();
System.out.println("First Name = " + f_name);
When sc.hasNext("[A-Za-z]*") returns true, that means the next input you read will be the one you want. So you need to read f_name in after the loop ends.
You still need sc.next() inside the loop to move past bad input; otherwise you will have an infinite loop.
By the way, perhaps you want to use + instead of * in your regular expression. * means "zero or more", and + means "one or more". I assume you want one or more characters to be input.
while (!sc.hasNext("[A-Za-z]+")) {
System.out.println(ANSI_RED + " ERROR: Invalid option!");
System.out.print(ANSI_RESET + " Type your name here (use only latin characters) > ");
sc.next();
}
String f_name = sc.next().toUpperCase();
This question says ask for the 'First Name' and the 'Last Name' from the user and then show the message Welcome with the full name of the user . also make sure that the user does not enter his/her full name in the first Text Field which asks for First Name only
I thought that if the user enters his/her full name in the first text field , we can know that from the fact that he/she entered a space or (' ') or not . If not we can simply show the message Welcome + full name . However it didn't work the way I thought it would ... Can somebody help me with itenter image description here
If I understand you the below will work accomplish what you need by ignoring the data after the space and asking the user for their last name.
code:
public static void main(String[] args) {
// Properties
Scanner keyboard = new Scanner(System.in);
String firstName, lastName
// Ask the user for their first name
System.out.println("What is your first name? ");
System.out.print("--> "); // this is for style and not needed
firstName = keyboard.next();
// Ask the user for their last name
System.out.println("What is your last name? ");
System.out.print("--> "); // this is for style and not needed
lastName = keyboard.next();
// Display the data
System.out.println("Your first name is : " + firstName);
System.out.println("Your last name is : " + lastName);
}
There is actually a few ways you can do this, but if I understand your question correctly a simple way would be below, which is from http://math.hws.edu/javanotes/c2/ex6-ans.html and helped me understand Java more when I was learning it, you just would alter it to your needs.
code:
public class FirstNameLastName {
public static void main(String[] args) {
String input; // The input line entered by the user.
int space; // The location of the space in the input.
String firstName; // The first name, extracted from the input.
String lastName; // The last name, extracted from the input.
System.out.println();
System.out.println("Please enter your first name and last name, separated by a space.");
System.out.print("? ");
input = TextIO.getln();
space = input.indexOf(' ');
firstName = input.substring(0, space);
lastName = input.substring(space+1);
System.out.println("Your first name is " + firstName + ", which has "
+ firstName.length() + " characters.");
System.out.println("Your last name is " + lastName + ", which has "
+ lastName.length() + " characters.");
System.out.println("Your initials are " + firstName.charAt(0) + lastName.charAt(0));
}
}
edit:
If this doesn't make sense I can give a better explanation with a better example with more detail.
More notes on similar problems.
https://www.homeandlearn.co.uk/java/substring.html
The problem with your code is, that you check every single charackter and then do the if/else for every single charackter. which means if the last charackter is not a whitespace it will at the end process the else tree.
The solution is to just check once:
if(fn.contains(' '){
//Do what you want to do, if both names were entered in the first field
}else{
//Everything is fine
}
I have a text file that holds data like this:
Jones,Mary,903452
4342,2.5,A
3311,4,B+
I'm using Scanner to read the file. This is my code:
while(reader.hasNextLine())
{
reader.useDelimiter(",");
String lastN = reader.next();
String firstN = reader.next();
String id = reader.nextLine();
String course1 = reader.next();
double credits = reader.nextDouble();
String grade = reader.nextLine();
}
But when I print the line on the console, the , on the last part of the line doesn't get delimited and it prints like this:
Jones, Mary, ,903452
4342, 2.5, ,A
6.5, ,3.569
My toString method on my class:
public String toString() {
return lastName + ", " + firstName + ", " + idNo + "\n"
+ courseOne + ", " + credits + ", " + grade;
I'm searched around for a solution. I tried reader.useDelimiter("[,]") and reader.useDelimiter(",|,") but still gives me the same output. How can I fix this?
From the Scanner's documentation:
This method returns the rest of the current line, excluding any line separator at the end. The position is set to the beginning of the next line.
(Emphasis mine) This means that the whole rest of the line is returned, including delimiters. Setting id to reader.next() wouldn't work because it sucks up everything until the next delimiter. A better solution would be to make it accept line breaks as a delimiter, like so:
reader.useDelimiter("[,\n]");
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Closed 9 years ago.
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i have to make a code that makes a star wars name generator and it asks for names but only takes certain letters from the name to come up with the star wars name, my program wont compile can anyone see what im doing wrong :
import java.util.Scanner;
public class StarWarsName {
public static void main(String[] args) {
System.out.printf("Enter your first name: ");
firstname = input.nextLine();
first = first.substring(0,3);
System.out.printf("Enter your last name: ");
lastname = input.nextLine();
last = last.substring(0,2);
System.out.printf("Enter your mother's maiden name: ");
mothersname = input.nextLine();
mother = mother.substring(0,2);
System.out.printf("Enter the name of the city in which you were born: ");
cityname = input.nextLine();
city = city.substring(0,3);
StarWarsName = first +" "+ last +" "+ mother +" "+ city + " of " + last +" "+$
System.out.println("May the force be with you, " + StarWarsName + "May the fo$
}
}
Starting with this line:
firstname = input.nextLine();
Hints:
1) Where is firstname declared?
2) Read the compilation error message!
3) When you ask someone else a question about a compilation error, you need to say what the compilation error was, and where it occurred.
And consider this line:
StarWarsName = first +" "+ last +" "+ mother +" "+ city + " of " + last +" "+$
4) The $ at the end is not valid Java. It looks like a copy and paste error. If a line in a Java program is too long to fit on your (anticipated) display device, it is common practice to split it; e.g.
StarWarsName = first +" "+ last +" "+ mother +" "+ city + " of " +
last + " " + and + " " + the + " " + rest;
You have several undeclared variables, eg firstname. I think there are also some logical mistakes, as you do not use firstname and others.
I need some help writing a program
Using this code I am able to enter in a track name, artist, etc.
I have a problem that I cannot now show this information in JOptionPane to display all of my info
import java.util.Scanner;
import javax.swing.JOptionPane;
public class TestTrack
{
public static void main(String[] args)
{
Scanner myScan = new Scanner(System.in);
System.out.println("Track name");
String name = myScan.nextLine();
System.out.println("Artist");
String Artist = myScan.nextLine();
System.out.println("Track length seconds");
String seconds = myScan.nextLine();
System.out.println("Album");
String Album = myScan.nextLine();
JOptionPane.showMessageDialog(null,"Trackinfo:")
}
}
So I guess I would want the pop out window to say
Track Name: "blank"
Artist: blank
Another question I have is how to ask this question multiple times by using "while" and asking if I would like to add another track
Sorry if I am using any terminology incorrectly I just started to learn Java
This line: JOptionPane.showMessageDialog(null,"Trackinfo:")
Contains what the pop-up window will contain. You pass in what you want its contents to be as the 2nd parameter, which is currently "Trackinfo".
To incorporate a while loop, you'll have to have a loop control variable, or a condition that will break the loop. In my example I used a string. My example uses a while loop that will continue as long as the string is not equal to "quit".
String test = "";
while( ! test.equals("quit") ) {
//use Scanner to get the next value the user enters
//ask for track info
//display that info in a message box
}
To obtain this:
Note: the texts of the OK and Cancel buttons are localized, if your computer is set to US locale you doesn't see 'Annuler"... ;-)
code this:
int answer = 0;
do {
/*----------------------------------------------------------------------------
Here you put the code which set the variables name, artist, seconds... (1)
----------------------------------------------------------------------------*/
final String title = "Track info";
final String message =
"<html><table>" +
"<tr><td>Track name" + "</td><td>" + name + "</td></tr>" +
"<tr><td>Artist" + "</td><td>" + artist + "</td></tr>" +
"<tr><td>Track length seconds</td><td>" + seconds + "</td></tr>" +
"<tr><td>Album" + "</td><td>" + album + "</td></tr>" +
"</table>";
answer =
JOptionPane.showConfirmDialog(
null, message, title, JOptionPane.OK_CANCEL_OPTION );
} while( answer == JOptionPane.OK_OPTION );
(1) You may choose Scanner or GUI whith JOptionPane.showInputDialog()
JOptionPane.showMessageDialog(null,"Trackinfo:" + "\nArtist: " + Artist + "\nseconds: " + seconds + "\nAlbum: " + Album)
Each '\n' means a new line. for doing this multiple times, you should place your code in a while loop, something like this:
while(!(Artist == "end")) {
//your code
}
Use myScan.next() instead of myScan.nextLine()
To output the information into the Message Dialog, use
String trackInfo = "Track Name: " + name + " | Artist : " +artist+ " | Track Length: " + seconds + " | Album: " + album;
JOptionPane.showMessageDialog(null, trackInfo, "Trackinfo", JOptionPane.INFORMATION_MESSAGE);