Develop Reference

I try to make a guess game and let user decide under what max number to guess

In oder to check the value entered by the user AND to see what random number has been calculated, I want to let those numbers projected in the console (eclipse). But what sketches my astonishment?? the last two system.out.println's (right above invoermax.close())) do NOT appear in the console screen after I entered the number???? It's like java doesn't even read or notice these code lines, How come???
Here my code:
package Package1;
import java.util.Scanner;
import java.util.concurrent.ThreadLocalRandom;
public class test6KOPIE1 {
public static void main(String[] args)
{
Scanner Invoermax = new Scanner(System.in);
System.out.println("Under which number you want to guess");
int Invoer = Invoermax.nextInt();
int Hoogte = ThreadLocalRandom.current().nextInt(1,Invoermax.nextInt());
System.out.println("So a guess under max: " + Invoer);
System.out.println("The random number has become " + Hoogte);
Invoermax.close();
}
}

every time you call Scanner.nextInt() it will wait for input from you.
The problem is that you are calling it twice, replace:
int Hoogte = ThreadLocalRandom.current().nextInt(1,Invoermax.nextInt());
With the variable you already got:
int Hoogte = ThreadLocalRandom.current().nextInt(1,Invoer);
And BTW, usually in java you start field/variable name with lower case letter, so should be hoogte, inoverMax, inover etc.

You can do something like this.
// code
Scanner Invoermax = new Scanner(System.in);
System.out.println("Under which number you want to guess");
int Invoer = Invoermax.nextInt();
Invoermax.nextLine(); // reading empty space left
int Hoogte = ThreadLocalRandom.current().nextInt(1,Invoermax.nextInt());
// code

You have two scanner.nextInt() calls, so there are two input readings, two input waitings.
int Invoer = Invoermax.nextInt(); // the first input reading
int Hoogte = ThreadLocalRandom.current().nextInt(1,
Invoermax.nextInt()); // the second input reading
When you enter two int values in a console (any of the kind) you'll see your ending print rows.
If your design was to have a single input, then use cashed value for the second usage
int Invoer = Invoermax.nextInt(); // the first input reading
int Hoogte = ThreadLocalRandom.current().nextInt(1,
Invoer ); // use cashed value

Matching user input against a string array in java?

I am incredibly new to java and have been given the following task:
Write a Java Program to prompt a user for a 3 letter body part name which has to be in the 'official' list of 3 letter body parts. (Arm, Ear, Eye, Gum, Hip, Jaw, Leg, Lip, Rib, Toe)
If a user makes a guess correctly then display the correct guess as part of a list.
Allow the user to keep guessing until they have all 10.
If a body part is incorrect then display an appropriate message.
Display the number of guesses they have made including
the correct ones.
The advice given was to use Arrays and Collections as well as Exception Handling where appropriate but I don't know where to go from what I've coded so far. Any help would be appreciated so much, thank you.
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String[] bodyparts = new String [10];
bodyparts[0] = "Arm";
bodyparts[1] = "Ear";
bodyparts[2] = "Eye";
bodyparts[3] = "Gum";
bodyparts[4] = "Hip";
bodyparts[5] = "Jaw";
bodyparts[6] = "Leg";
bodyparts[7] = "Lip";
bodyparts[8] = "Rib";
bodyparts[9] = "Toe";
Set<String> bodypartSet = new TreeSet<>();
Collections.addAll(bodypartSet, bodyparts);
System.out.println("Please enter a 3 letter body part: ");
String bodypart = input.nextLine();
if (bodypartSet.contains(bodypart)) {
System.out.println("Correct, " + bodypart + " is on the list!");
} else {
System.out.println("Nope, try again!");
}
}

There are a lot of way to do this. The following, isn't the best or the most efficient, but it should work...
First of all, you have to put your "official" list in a structure, like an array:
private static String[] offList={Arm, Ear, Eye, Gum, Hip, Jaw, Leg, Lip, Rib, Toe};
Now you have to write a method that can find a world in that "offList", like that:
private static boolean find(String word){
for( int i=0; i<offList.length; i++){
if(word.equals(offList[i])) //if "word" is in offList
return true;
}
return false;
}
Now, let's create this guessing game GUI:
public static void main(String[] args){
LinkedList<String> guessed=new LinkedList<>();
String s;
Scanner input = new Scanner(System.in);
while(guessed.size()<offList.length){
System.out.println("Guessed= "+guessed.toString()); //you have to change it, if you want a better look
System.out.print("Try:");
s=input.nextLine();
/*Here we ask to the user the same thing, unless the guessed list
contains all the words of offList.
Every time we print the guessed worlds list*/
if(find(s)){
System.out.println("This world is in offList!");
if(!guessed.contains(s)) //the world is counted only one time!
guessed.add(s);
}else
System.out.println("Sorry...");
}
System.out.println("The complete list is "+guessed.toString());
}
If you want to show this game in a window, you should have to study some Java Swing classes.
EDIT: I post my answer before the main post editing. First of all you have to understand the Collections advantages and usage... When you know all the LinkedList methods, for example, this assignment looks like a joke! ;)

You need a loop for that, otherwise it will only ask for input once.
Something like this should do:
ArrayList<String> bodyParts = new ArrayList<String>();
bodyParts.add("Arm");
bodyParts.add("Ear");
bodyParts.add("Eye");
bodyParts.add("Gum");
bodyParts.add("Hip");
bodyParts.add("Jaw");
bodyParts.add("Leg");
bodyParts.add("Lip");
bodyParts.add("Rib");
bodyParts.add("Toe");
String input = "";
int totalGuesses = 0;
Scanner sc = new Scanner(System.in);
System.out.println("Start guessing...");
while (!bodyParts.isEmpty()) {
totalGuesses++;
input = sc.nextLine();
if (input.length() != 3 || !bodyParts.contains(input)) {
// incorrect, do nothing
System.out.println("Nope.");
} else {
// correct, remove entry
bodyParts.remove(input);
System.out.println("Correct! " + (10 - bodyParts.size()) + " correct guess" + ((10 - bodyParts.size()) != 1 ? "es" : ""));
}
}
System.out.println("Done. You have found them all after " + totalGuesses + " guesses.");
sc.close();
Also, this is case sensitive. It will not find Arm when typing arm. And if you need the number of all guesses you can simply add an int before the loop and increase it inside.
The result of my example:
Start guessing...
arm
Nope.
Arm
Correct! 1 correct guess
Arm
Nope.
Ear
Correct! 2 correct guesses
Eye
Correct! 3 correct guesses
(...)
Rib
Correct! 9 correct guesses
Toe
Correct! 10 correct guesses
Done. You have found them all after 12 guesses.

Check String is in a range of numbers Java

Trying to design a simple lottery program. Everything works except checking if the numbers entered are between 1 to 59.
Exercise says the numbers must be stored in a String variable.
so
if(num<0 || num>59) //wont work for me
Tried making another variable
int numConverted = Integer.parseInt(num)
We haven't covered converting String to int in class though so I don't think this is what expected. Got confused trying that way anyway so probably this is wrong.
Here is the code I have currently.
{
Scanner scan = new Scanner(System.in);
String num=""; //num variable is empty untill user inputs numbers
for(int i =0; i<6; i++)
{
System.out.println("Enter your number between 1-59");
num = num +" "+ scan.nextLine();
}
System.out.println("Ticket printed £2. Your numbers are " + num);
}

In your posted code it's obvious that you want the User to supply 6 specific numerical values. These values are appended to the String variable named num (space delimited). You need to obviously do a few things here:
1) Make sure the value supplied by the user is indeed a numerical value;
2) Make sure the numerical values supplied fall within the minimum and maximum scope of the lottery itself (which you have stated is: 1 to 59);
3) Make sure the number entered by the User hasn't been supplied already.
You've been tasked to store the entered values into a String data type variable and that is all fine but at some point you want to carry out value comparisons to make sure that all the entered values actually play within the limits of the lottery.
When the User completes his/her entries, you end up with a space delimited string held in the num string variable. You now need to make sure that these values entered are indeed....numbers from 1 to 59 and none contain alpha characters.
In my opinion (and this is only because you need to store entered values into a String variable), it's best to use your String variable to gather User input, then test the input to make sure it is indeed a string representation of an actual integer number. Once this is established then we test to make sure if falls within the value min/max limits (1-59). Now we need to test to make sure the number entered hasn't already been entered before for this ticket.
Of course with each test described above, if one fails then the User should be prompted to re-enter a proper value. You can do this by utilizing a while loop. Plenty examples of this in StackOverflow but here's a quick example:
Scanner scan = new Scanner(System.in);
String ticketNumbers = "";
for(int i = 0; i < 6; i++) {
Boolean isOK = false;
while (!isOK) {
System.out.println("\nPlease enter your desired 6 ticket numbers:\n"
+ "(from 1 to 59 only)");
String num = scan.nextLine();
//Is the string entered an actual integer number?
//We use the String.matches() method for this with
//a regular expression.
if(!num.matches("\\d+")) {
System.out.println("You must supply a numerical value! "
+ "Try Again...");
continue;
}
if (ticketNumbers.contains(num + " ")) {
System.out.println("The number you supplied has already been chosen!"
+ " Try Again...");
continue;
}
if (Integer.parseInt(num) >= 1 && Integer.parseInt(num) <= 59) {
ticketNumbers+= num + " ";
isOK = true;
}
else {
System.out.println("The number you supply must be from "
+ "1 to 59! Try Again...");
}
}
}
System.out.println("Ticket printed £2. Your numbers are " + ticketNumbers);

How about -
if(Integer.parseInt(num) < 0 || Integer.parseInt(num) > 59)
This should work, place it after the input.
If it works, please mark this as correct, I need the rep!!!

Easy way would be add available numbers (suppose it wont grow more than 60. You can use a loop to add to this as well)
String numbers[] = {"1","2","3", "..."};
Then inside the loop
Arrays.asList(numbers).contains(num);
You can remove prefixing zero in order avoid conflicts with values like '02'
Here everything is String related.

If you don't want to explicitly convert to int, you could use a regular expression.
if (num.matches("[1-5]?[0-9]")) {
...
This checks whether the String consists of (1) maybe a digit from 1 to 5, followed by (2) definitely a digit from 0 to 9. That'll match any number in the range 0-59.
If you've got a whole series of numbers separated by spaces, you could expand this to cover a whole series like this.
if (num.matches("([1-5]?[0-9]\\s+)*[1-5]?[0-9]")) {
This matches any number of repetitions (including zero) of "a number followed by spaces", followed by a single repetition without a space. The "\\s" means "any whitespace character", the "+" after it means "one or more of what precedes", and the "*" means "zero more of what precedes" - which in this case is the term in parentheses.

Oh I see what you are trying to do
This is what you want
Scanner scan = new Scanner(System.in);
String allNums = "";
for(int i =0; i<6; i++)
{
System.out.println("Enter your number between 1-59");
int num = scan.nextInt();//Take the number in as an int
if(num >0 && num < 59)//Check if it is in range
{
allNums += num + " ";//if it is add it to a string
}
else
{
System.out.println("Number not in range");
i--;//go back one iteration if its not in range
}
}
System.out.println("Ticket printed £2. Your numbers are " + allNums);

Using ints/doubles and Strings in the same Scanner variable

So I'm new to java programming, coming from Python, and there's a few concepts that I can't quite understand.
I'm writing a program which allows the user to enter as many numbers as they want and the program should output the average of all of the numbers. I used a while loop to loop through the inputs by the user as many times as they wanted, but I needed a way of exiting the loop so that the program could proceed with calculating the average of all of the inputs. I decided that if the user enters an "=" sign instead of a number, then the program would break out of the loop, but since the Scanner variable was looking for a double, and the "=" sign is not a number, I would have to make it a String. But because the Scanner is looking for a double, the program threw an error when it encountered the "=".
How can I get the program to exit the loop when the user types "="? I know I could just allow the user to enter a number that breaks the loop, but if it was a real world program and the user entered a number, it would count that number along with the previous ones when calculating the average. The code I have so far is as follows:
import java.util.Scanner;
// imports the Scanner class
public class Average{
public static void main(String[] args){
double num, total = 0, noOfInputs = 0, answer;
Scanner scanner = new Scanner(System.in);
while(true){
System.out.print("Enter number: ");
//Prompts the user to enter a number
num = scanner.nextDouble();
/*Adds the number inputted to the "num" variable. This is the
source of my problem*/
if(num.equals("=")){
break;}
/*The if statement breaks the loop if a certain character is
entered*/
total = total + num;
//Adds the number inputted to the sum of all previous inputs
noOfInputs++;
/*This will be divided by the sum of all of the numbers because
Number of inputs = Number of numbers*/
}
answer = total / noOfInputs;
System.out.print(answer);
}
}

Several ways to do this.
You could read every number as a string, and then if it is a number, parse it to get the value.
Integer.parseInt(String s)
Or you could check what comes next and read accordingly:
while (scanner.hasNext()) {
if (sc.hasNextInt()) {
int a = scanner.nextInt();
} else if (scanner.hasNextLong()) {
//...
}
}
Or you could just catch the InputMismatchException, and work from there.
try{
...
} catch(InputMismatchException e){
//check if '=' ...
}

Entering Same number twice in an array

Any possible way to keep entering numbers, and when the same number is entered 2 or more times an error message arises or something like that? I need this to be answered in Java only. I'm new and I don't know where to go from here. I need help searching values in the array and then printing out all the numbers that have been entered.
public class Test
{
public static void main(String args[])
{
Scanner input = new Scanner(System.in);
System.out.println("How big is the group?: ");
int[] group = new int[input.nextInt()];
for (int i = 0; i < group.length; i++)
{
System.out.println("Please enter number: ");
group[i] = input.nextInt();
}

I think this is what you're looking for. Inside of the for loop, there's a while loop spinning to keep collecting new ints until you enter one that's not already in the list.
for (int i = 0; i < group.length; i++)
{
System.out.println("Please enter number: ");
int next = input.nextInt();
while(Arrays.asList(group).contains(next)) { // Keep asking for new input while the input is already in list
System.out.println("That number is already in the group ... try again.");
next = input.nextInt();
}
group[i] = next;
}

Since this is clearly a "learning exercise", it is only appropriate to give you hints:
You can search an array by stepping through the array indexes and testing the elements at each index.
A method and a class both need a closing } ...
I need this to be answered in Java only.
That is incorrect. What you REALLY need is some hints. If we give you Java code, you miss out on the important learning experience of writing it yourself. And THAT is the WHOLE POINT of the homework. Go ask your teacher if you don't believe me.