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.
Related
I am trying to take an integer as user input and store it in a list until the user hits 'q'. At the moment the user inputs 'q', the loop gets terminated.
The code is showing an InputMismatch error:
import java.util.*;
public class SampleArrayList {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s;
int n;
List<Integer> array = new ArrayList();
while (true) {
n = sc.nextInt();
s = sc.nextLine();
if (s.equals("q")) {
break;
} else {
array.add(n);
}
}
Collections.sort(array);
System.out.println(array);
}
}
Just try this,
Inside your while loop to get input for a string use,
s = sc.next();
Instead of sc.nextLine();.
Are you trying to implement it like the example below?
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
String s;
List<Integer> array = new ArrayList();
while (true) {
s = sc.nextLine();
if (s.equalsIgnoreCase("q")) {
break;
}
int num = Integer.parseInt(s);
array.add(num);
}
Collections.sort(array);
System.out.println(array);
}
}
Looks like q is trying to be stored as an int, so this should work:
All numbers stored as a String can be parsed as an int with the parseInt() method.
s = sc.nextLine();
if (!s.equals("q"))
{
array.add(Integer.parseInt(s));
}
else
{
break;
}
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()).
Here's what I have so far from my code. this is an introductory course so we haven't covered more advanced topics yet. With what I gave so far I input number and press -1 but the program doesn't do anything.
WE HAVEN'T COVERED ARRAYS YET.
import java.util.Scanner;
public class DataSet {
private double value,count,sum, sumOfSquares, average;
public DataSet(double value)
{
this.value=value;
}
public double getAverage(){
int value=0;
int count=0;
double sum=0;
while(value != -1){
sum=sum+value;
average=sum/count;
}
return average;
}
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.print("Enter a numbers to get average and standard deviation: ");
int value=input.nextInt();
DataSet s= new DataSet(value);
System.out.println(s.getAverage());
}
}
Try this below program. This class has only average method. You can add any number methods operating on values arraylist.
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class DataSet {
private List<Integer> values;
public DataSet(List<Integer> values) {
this.values = values;
}
public double getAverage() {
int sum = 0;
double result = 0.0;
for (int value : values) {
sum = sum + value;
}
if (values.size() > 0) {
result = sum / values.size();
}
return result;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
List<Integer> values = new ArrayList<Integer>();
System.out
.print("Enter a numbers to get average and standard deviation: ");
int value = input.nextInt();
while (value != -1) {
values.add(value);
value = input.nextInt();
}
DataSet s = new DataSet(values);
System.out.println(s.getAverage());
}
}
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
I have traced through this code and can't figure out how to fix it. When running the code why wouldn't the user be prompted for input rather than Java determining that there is no input? Error trace below.
import java.util.*;
public class SortAsInserted {
public static void main(String[] args) {
int array_size = GetArraySize();
//System.out.println(array_size);
String[] myArray = new String[array_size];
for (int i = 0; i < array_size; i++){
String next_string = GetNextString();
System.out.println(next_string);
}
}
//public static String[] SortInsert(String nextString){
//}
public static int GetArraySize(){
Scanner input = new Scanner(System.in);
System.out.print("How many items are you entering?: ");
int items_in_array = input.nextInt();
input.close();
return items_in_array;
}
public static void PrintArray(String[] x) {
for (int i = 0; i < x.length; i++){
System.out.print(x[i]);
}
}
public static String GetNextString(){
Scanner input = new Scanner(System.in);
System.out.println("Enter the next string: ");
String next_string = input.nextLine();
input.close();
return next_string;
}
Here is the error --
How many items are you entering?: 2
Enter the next string:
Exception in thread "main" java.util.NoSuchElementException: No line found
at java.util.Scanner.nextLine(Unknown Source)
at SortAsInserted.GetNextString(SortAsInserted.java:40)
at SortAsInserted.main(SortAsInserted.java:10)
The simple answer is when you close Scanner -- underlying input stream also closes:
http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html#close()
To fix this create Scanner once in main:
public class SortAsInserted {
static Scanner input;
public static void main(String[] _) {
input = new Scanner(System.in);
....
input.close();
}
Remove input.close(); from the code
Removing the scanner.close() method from two functions will solve your problem.
import java.util.*;
public class SortAsInserted {
public static void main(String[] args) {
int array_size = GetArraySize();
//System.out.println(array_size);
String[] myArray = new String[array_size];
for (int i = 0; i < array_size; i++){
String next_string = GetNextString();
System.out.println(next_string);
}
}
//public static String[] SortInsert(String nextString){
//}
public static int GetArraySize(){
Scanner input = new Scanner(System.in);
System.out.print("How many items are you entering?: ");
int items_in_array = input.nextInt();
//input.close();
return items_in_array;
}
public static void PrintArray(String[] x) {
for (int i = 0; i < x.length; i++){
System.out.print(x[i]);
}
}
public static String GetNextString(){
Scanner input = new Scanner(System.in);
System.out.println("Enter the next string: ");
String next_string = input.nextLine();
// input.close();
return next_string;
}
}