Hi there I am super new to coding and I keep getting a '.class' error when I try to run the code below. What am I missing?
import java.util.Scanner;
import java.util.Scanner;
public class PeopleWeights {
public static void main(String[] args) {
Scanner scnr = new Scanner (System.in);
userWeight = new int[5];
int i = 0;
userWeight[0] = 0;
userWeight[1] = 5;
userWeight[2] = 6;
userWeight[3] = 7;
userWeight[4] = 9;
System.out.println("Enter weight 1: ");
userWeight = scnr.nextInt[];
return;
}
}
This is the problem
userWeight = scnr.nextInt[];
Solve this by:
userWeight[0] = scnr.nextInt(); //If you intended to change the first weight
OR
userWeight[1] = scnr.nextInt(); //If you intended to change the value of userWeight at index 1 (ie. the second userWeight)
Should work
PS: As a precaution do not import the Scanner class twice. Doing it once would be enough
I understood your intension and below are two possible ways to implement your thought:
I see you are giving values manually as userWeight[0]=0;
If you wanna give manually I suggest not to go with scanner as below.
public static void main(String[] args) {
int[] userWeight={0, 5, 6,7,9};
System.out.println("Weights are" +userWeight);//as you are giving values.
}
If your intension is to get values at run time or from user, please follow below approach
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
System.out.println("This is runtime and you need to enter input");
int[] userWeight = new int[5];
for (int i= 0; i < userWeight.length; i++) {
userWeight[i] = sc.nextInt();
System.out.println(userWeight[i]);
}
}
PS:
I seen you are using util package import for two times, instead you may import all at once as import java.util.*;
Also you are trying to return. Please note for void methods its not need for return values. VOID excepts nothing in return.
First of all do not import packages more than once, now lets go to the actual "bugs".
Here:
import java.util.Scanner;
public class PeopleWeights {
public static void main(String[] args) {
Scanner scnr = new Scanner (System.in);
int userWeight[] = new int[5];//You need to declare the type
//of a variable, in this case its int name[]
//because its an array of ints
int i = 0;
userWeight[0] = 0;
userWeight[1] = 5;
userWeight[2] = 6;
userWeight[3] = 7;
userWeight[4] = 9;
System.out.println("Enter weight 1: ");
userWeight[0] = scnr.nextInt();//I belive that you wanted to change
// the first element of the array here.
//Also nextInt() is a method you can't use nextInt[]
//since it doesn't exists
//return; You dont need it, because the method is void, thus it doesnt have to return anything.
}
}
Also instead of this:
userWeight[0] = 0;
userWeight[1] = 5;
userWeight[2] = 6;
userWeight[3] = 7;
userWeight[4] = 9;
you can do this during the declaration of an array:
int userWeight[] = {0,5,6,7,9};//instantiate it with 5 integers
Related
Here I am trying to find the max and min number entered into the array so I'm using a min and a max method(not declared yet) but I'm not quite sure how to access my array in these methods as the array userArray and array are not in the scope of the method and can't be accessed. can someone help me out?
package edu.skidmore.cs106.lab07.problem1;
import java.util.Scanner;
public class numberArray {
//Method to take user input
public int[] getUserData() {
System.out.println("How many numbers will you enter?");
Scanner keyboard = new Scanner(System.in);
// Create variable to store user's desired number of values
int totalNumbers = keyboard.nextInt();
// Declare and initialze an array
int[] userArray = new int[totalNumbers];
// Create a loop to ask for values from the user
// Within the loop, store user input in the array
for (int x = 0; x < totalNumbers; ++x) {
System.out.println("Enter number " + x);
int userInput = keyboard.nextInt();
userArray[x] = userInput;
}
return userArray;
}
public int minNumber() {
for (int y : array)
}
public static void main(String[] args) {
numberArray instance = new numberArray();
int array[] = instance.getUserData();
for (int element: array){
System.out.println(element);
}
}
}
public int minNumber(int[] userDataArray) {
// use userDataArray here
}
...
public static void main(String[] args) {
numberArray instance = new numberArray();
int[] userDataArray = instance.getUserData();
int min = instance.minNumber(userDataArray); // pass userDataArray as argument
}
i'm trying to write a program that reads a file and then prints it out and then reads it again but only prints out the lines that begin with "The " the second time around. it DOES print out the contents of the file, but then it doesn't print out the lines that begin with "The " and i can't figure out why. it prints out the println line right before the loop, but then it ignores the for-loop completely. the only difference between my findThe method and my OutputTheArray method is the substring part, so i think that's the problem area but i don't know how to fix it.
import java.util.*;
import java.io.*;
public class EZD_readingFiles
{
public static int inputToArray(String fr[], Scanner sf)
{
int max = -1;
while(sf.hasNext())
{
max++;
fr[max] = sf.nextLine();
}
return max;
}
public static void findThe(String fr[], int max)
{
System.out.println("\nHere are the lines that begin with \"The\": \n");
for(int b = 0; b <= max; b++)
{
String s = fr[b].substring(0,4);
if(s.equals("The "))
{
System.out.println(fr[b]);
}
}
}
public static void OutputTheArray(String fr[], int max)
{
System.out.println("Here is the original file: \n");
for(int a = 0; a <= max; a++)
{
System.out.println(fr[a]);
}
}
public static void main(String args[]) throws IOException
{
Scanner sf = new Scanner(new File("EZD_readme.txt"));
String fr[] = new String[5];
int y = EZD_readingFiles.inputToArray(fr,sf);
EZD_readingFiles.OutputTheArray(fr,y);
int z = EZD_readingFiles.inputToArray(fr,sf);
EZD_readingFiles.findThe(fr,z);
sf.close();
}
}
this is my text file with the tester data (EZD_readme.txt):
Every man tries as hard as he can.
The best way is this way.
The schedule is very good.
Cosmo Kramer is a doofus.
The best movie was cancelled.
Try cloning sf and passing it to the other function.
Something like this:
Scanner sf = new Scanner(new File("EZD_readme.txt"));
Scanner sf1 = sf.clone();
int y = EZD_readingFiles.inputToArray(fr,sf);
EZD_readingFiles.OutputTheArray(fr,y);
int z = EZD_readingFiles.inputToArray(fr,sf1);
EZD_readingFiles.findThe(fr,z);
sf.close();
sf1.close();
I wish to create a list, and the list has a input as length, however after I put in the preferable length as input, the list won't show up;
import java.util.ArrayList;
import java.util.Scanner;
public class JJ {
public static void main(String args[]) {
JJ.getalist();
}
public static ArrayList<Integer> getalist(){
ArrayList<Integer> JJ = new ArrayList<Integer>();
System.out.println("Oh, How long would you want your list to be?");
Scanner in = new Scanner(System.in);
int length = in.nextInt();
for (int i=0; i<length; i++) {
int point = (int) (Math.random()*9);
JJ.add(new Integer(point));
}
return JJ;
}
}
You didn't use System.out.println() in the main method when invoking JJ.getalist(). You can pass JJ.getalist() return value as the argument of the method printing to the console like this:
System.out.println(JJ.getalist()).
import java.util.Scanner;
import java.util.Arrays;
public class CarCareChoice{
public static void main(String[] args) {
String[] choices=new String[5];
int j ;
boolean validItem=false;
double price=0.0;
int p;
String str;
//When i'm entering services I'm getting 5.o for all services plz help
String[] services={"Am","Bm","Cm","Dm","Em"};
double prices[]={1.0,2.0,3.0,4.0,5.0};
//Scanner
Scanner input = new Scanner(System.in);
System.out.println("enter");
str= input.nextLine();
for(j = 0; j < choices.length;j++){
if(Arrays.asList(services).contains(str)){
validItem=true;
price=prices[j];
}
}
if (validItem)
System.out.println("service"+""+price);
else
System.out.println("Invalis enter");
}
}
output
enter
Am
service5.0
output
enter
Bm
service5.0
when I enter Am i supposed to get 1.0 for "Bm 2.0 and etc but I'm getting only 5.0
You rather improve your code as following:
System.out.println("enter");
List<String> choiceList = Arrays.asList(services);
str= input.nextLine();
int index = choiceList.indexOf(str);
if ( index!=-1 )
{
price = prices[i];
validItem = true;
}
if (validItem)
System.out.println("service"+""+price);
else
System.out.println("Invalis enter");
You need not do this in for loop. Because when you have converted your array to a list then just find the index. If that is -1 then its definitely not a valid item else return the price at that index of the array. ArrayList is backed by an array internally.
import java.util.Arrays;
class Main {
public static final int INVALID_INDEX = -1;
public static void main(String[] args) {
String[] services={"Am","Bm","Cm","Dm","Em"};
double prices[]={1.0,2.0,3.0,4.0,5.0};
String input = "Em";
int index = Arrays.asList(services).indexOf(input);
System.out.println((index!=INVALID_INDEX)? prices[index]+"":"invalid input");
}
}
Use a Map<String,Double> instead if possible.
I'm working on a Guessing Game that will uses arrays to store both the names of all the players and their guesses. I'm fairly new to arrays, so my plan to get user input into the array was to get them to enter the amount of people playing, set that up as a variable and then use a loop to keep asking for names until I reached the necessary amount of names for the stated number of players. However, I am running into what probably is a very simple problem with the loop. Here's a small bit of my code thus far:
public class GuessGame {
int w = 0;
int[] Players = new int[100];
String[] PlayerNames = new String[100];
String numStart = JOptionPane.showInputDialog("How many players?");
int j = Integer.parseInt(numStart);
while (w <= j)
{
String Name = JOptionPane.showInputDialog("What is your name?");
PlayerNames[w] = Name;
w++;
}
The problem is, I'm getting an error regarding the variables in my loop, w and j. The error statement says something to the effect of it cannot find the symbols for class w or class j. I don't intend for them to be classes, and I've run similar code in other projects without a hitch, so I really don't know what's going wrong here. I'm sure it's something stupidly simple, but *'ve been stuck at this wall for some time now and can't really progress until I get this sorted. This is part of a project with three separate classes. The class posted here, a Player class, and a Tester class, which is my main method. I had the whole thing working in a more simplified form earlier, but now I need to adjust it for actual player input and the arrays. Regardless, the tester class is supposed to be my main class. I am using Netbeans if it matters. Thank you. Here are the other two classes for reference:
package GuessGame;
public class GameLauncher {
public static void main(String[] args) {
GuessGame game = new GuessGame();
game.startGame();
}
}
and
package GuessGame;
import java.util.Random;
public class Player {
int number = 0; //where guess goes
String name;
public void guess() {
Random r = new Random();
number = 1 + r.nextInt(21);
System.out.println("I'm guessing " + number);
}
}
All your code needs to be in a method. You cannot have anything except variable declarations at the class level. Move all this into a method, for example public static void main(String[] args) main method.
public class GuessGame {
public static void main (String[] args)
{
int w = 0;
int[] Players = new int[100];
String[] PlayerNames = new String[100];
String numStart = JOptionPane.showInputDialog("How many players?");
int j = Integer.parseInt(numStart);
while (w <= j)
{
String Name = JOptionPane.showInputDialog("What is your name?");
PlayerNames[w] = Name;
w++;
}
}
}
public class GuessGame {
public void getPlayerName()
{
int w = 0;
int[] Players = new int[100];
String[] PlayerNames = new String[100];
String numStart = JOptionPane.showInputDialog("How many players?");
int j = Integer.parseInt(numStart);
while (w <= j)
{
String Name = JOptionPane.showInputDialog("What is your name?");
PlayerNames[w] = Name;
w++;
}
}
public static void main (String[] args)
{
GuessGame gg = new GuessGame();
g.getPlayerName();
}}
You can put in the methos as well and execute in the main method. But, if you declaring any variable inside the method (local variable), the variable must be initialised. Refer here for more details.
public class GuessGame
{
static int w = 0;
int[] Players = new int[100];
static String[] PlayerNames = new String[100];
public static void main(String[] args) {
// TODO Auto-generated method stub
String numStart = JOptionPane.showInputDialog("How many players?");
int j = Integer.parseInt(numStart);
while (w <= j)
{
String Name = JOptionPane.showInputDialog("What is your name?");
PlayerNames[w] = Name;
w++;
}
}
}
Everything should be in a method except variables.Class is template for variables and methods !!