How To Use For Loop To Calculate Product Of Consecutive Numbers
Feb 26, 2015
I wanted to know if I was off to the right start. I am trying to write a program using the for loop the calculate the product of the consecutive numbers 4 through 8 but so for I am getting 3 values output and I only want 1 value at the print out.
The code I am using outputs the numbers too large. I am trying to see where I went wrong.
for ( int i = 4 ; i <= 8; i++)
{
int j = i++;
int k = j++;
int l = k++;
int m = l++;
System.out.println( + (i*j*k*l*m) );
}
So basically, I've been trying to create a for loop that asks the user for a number between 1 and 30, then calculates the total of the series of numbers. For example, if 15 is entered, the calculation should be 1/15+2/14+3/13+...15/1 which would equal approximately 38.1. The problem I'm having is that the code doesn't loop whenever I type a number for some reason, which results in a very incorrect calculation. Here is my code so far:
import java.util.Scanner; public class HmwLoop { public static void main(String[] args) { double sum = 0; for (double num1 = 1, num2 = 30; num1 <= 30 && num2 >= 1; num1++, num2--)
im trying to do a program to find if numbers are consecutive or not! if they are consecutive i need a true as a return and a false when they are not... i did this program and im sure i did something wrong because i keep only true returns ..
Example: (3,5,7) (1,2,2) (7,7,9) should return a false! Java Code: import java.util.*; public class Consecutive{ public static void main (String [] args){ Scanner console= new Scanner(System.in); System.out.println("Enter three numbers"); String numbers = console.nextLine(); System.out.println( "The numbers (" + numbers + ") is '" + consecutive( numbers ) + "'" ); }//end of main
I have the following program. In a nutshell, I creates an array of 3 consecutive ints and the user has to guess what those numbers are, knowing that they are between 0 and 7, this is from Head First Java. In the book, the code has a bug that is made on purpose and they challenge you to fix it. As you can see bellow, every time a user's guess matches a int in the array, the NumOfHits is increased by one. When the NumOfHits is 3 (the length of the array) the game finishes.
The bug is that if you guess 1 and 1 is in the array, if you type in 1, 3 times, I will increase the NumOfHits 3 times and end the game as if you had won. To solve the bug, you need to find a way to tell the program that if the user already guessed that number, it should no longer be taken into account and we shouldn't increase the NumOfHits if the same number is provided.
I "fixed" this by searching for the index of the number that matches an int of the array, and changing that index's value to 100, since the user knows that the numbers are between 0 and 7, they will not submit 100.
The result? If the user submits 2 and 2 is in the array, the value of its indexed is replaced by 100, so that if the user submits 2 again it doesn't count as a match.
Please see the comments in the code
import java.io.*; import java.util.Arrays;
class DotCom{ int NumOfHits = 0; int[] LocationCells; public void setLocationCells(int[] locs){ LocationCells = locs;
[Code] .....
The code works, but for some reason, some times I get a ArrayIndexOutOfBoundsException run time error and it appears to be somehow random. This is what I saw on the command line earlier
C:Userspablo.alvarez>java launchDotCom
Enter a number: 3 missed Enter a number: 4 hit Enter a number: 5 hit Enter a number: 7 missed Enter a number: 5 missed Enter a number: 4 missed Enter a number: 3 missed Enter a number: 4 missed Enter a number: 5 missed Enter a number: 6
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: -1 at DotCom.checkYourSelf(launchDotCom.java:16) at DotComGame.startGame(launchDotCom.java:59) at launchDotCom.main(launchDotCom.java:72)
As you can see here, 3 returned 'missed' but 4 and 5 returned hit. Since the numbers are in sequence and are only 3, it makes sense that the last number is 6 (4,5,6). You will then notice that when I submitted 3 and 4 again it returned 'missed' as expected, because the numbers were already matched earlier, but then when I submitted 6, it returned the error seen above.
Sometimes this doesn't happen at all, sometimes it happens at the 2nd guess or third, it appears to be somehow random. I'm familiar with the error message, but I don't see where I'm using an index that doesn't exist in the array. The only time I'm referencing an array index is on
LocationCells[index] = 100;
but the index variable will only hold a value if the int submitted by the user matches on of the values in one of the indexes, so how is it that I'm going over the number of available indexes?
What I am trying to do here is allow input to loop until 0 is entered for the product number. When 0 is entered, it should then dump the total for each individual product. I've tried it about a dozen different ways and have yet to be able to get the loop to function as intended. The way I have the code below, the loop will not function at all (where as before it looped, but never finished).
import java.util.Scanner; public class Sales { public static void main(String[] args) { double total1=0.0; double total2=0.0; double total3=0.0; double total4=0.0; double total5=0.0; int product;
The Program prompts the user to enter the number of products in the product catalog. The program should then prompt the user for the name and the price of each product in the product catalog. Once all of the products have been entered, the program should output the product information (name and price) of the most expensive product in the catalog. Your solution to keep track of the product with the highest price.
import java.util.Scanner; public class ProductTester { private static final String price = null; public static void main(String[] args) { Scanner console = new Scanner(System.in); System.out.print("Enter the number of Products: "); int count = console.nextInt();
It's suppose to generate a table with the month, and the new amount of the CD. Right now, the program generates a continuous table for months, but it doesn't update the value of the CD.
import java.util.*; public class Excercise04_31 { public static void main(String[] args) { // TODO Auto-generated method stub Scanner input = new Scanner(System.in);
having some trouble doing this. Here are the requirements:
1)Write a program using loop and break to calculate the value of PI. 2)You can use the following equation to calculate PI. PI=4/1-4/3+4/5-4/7+4/9-4/11+4/13 etc.. The program shouldn't loop until the criteria is satisfied. 3)The criteria is the value of PI you get is very close to the “real” value (3.1415926), meaning that their difference should be smaller than a very small numeric number, e.g., 0.0001). 4)The control structures you may need for this program are loop, if-else, and unlabeled break. 5)The output should have the format: for each iteration, it has iteration number and the corresponding value of PI until that iteration. The last line would be the final value of PI.
Here is my code so far:
package ids; public class IDS { public static void main(String[] args) { double pi = 0; for(int i=1; i<=100000; i++){ if ((i%2)==0){ pi+=(4/(2*i-1));
I'm trying to write a program that calculates the factorials of the numbers 1 through 10, based on user input... My problem is that I don't know how to address the possibility of the user entering something other than a number. When I test the following code by entering a letter, I get an Input Mismatch exception. I'd like to be able to inform the user that the entry is invalid, and ask for another response. Here is my program thus far:
Java Code:
import java.util.Scanner; public class Factorial { public static String entryString; public static char entryChar; public static Scanner input = new Scanner(System.in);
So I've attempted a for loop for this type of problem:If you receive $0.01 on the first day of your allowance, and the daily rate doubles each day after, calculate the total earnings for 30 days.
Output should be like: Day ----- Daily allowance - Total allowance 1 -------- 0.01 -------------- 0.01 2 -------- 0.02 -------------- 0.03 3 -------- 0.04 -------------- 0.07
My code so far:
public class Allowance { public static void main (String[] args) { int day = 0; double daily = 0.0; double total = 0.1; System.out.println("Day Daily Allowance Total Allowance"); for(day = 0; day <= 30; )
I am trying to write a loop that calculates the distance traveled (distance = speed * time). It should use the loop to calc how far the vehicle traveled for each hour of time. My program asks for hours and then mph but its not calculating time * speed. Here is my code.
public static void main(String[] args) { Scanner input = new Scanner(System.in); System.out.println("Enter Hours Traveled "); int hoursTraveled = input.nextInt(); System.out.println("Enter MPH "); int mph = input.nextInt();
Write method distance to calculate the distance between two points (x1, y1) and (x2, y2). All numbers and return values should be of type double. Incorporate this method into an application that enables the user to enter the coordinates of the points.
Hints:
- The distance between two points can be calculated by taking the square root of
( x2 - x1 )2 + ( y2 - y1 )2
- Use Math class methods to compute the distance.
- Your output should appear as follows:
Type the end-of-file indicator to terminate
On UNIX/Linux/Mac OS X type <ctrl> d then press Enter
On Windows type <ctrl> z then press Enter
Or Enter X1: 1
Enter Y1: 1
Enter X2: 4
Enter Y2: 5
Distance is 5.000000
Type the end-of-file indicator to terminate
On UNIX/Linux/Mac OS X type <ctrl> d then press Enter
The purpose of this program is to import via keyboard Numbers.txt and calculate the mean and standard deviation to Results.txt.I am able to get the mean calculate but when I open the Results.txt the standard deviation is 0. I don't know what is wrong with my code, but I believe it has something to do with the scanner being close. Here is the error message i receive after inputting Numbers.txt.
java.lang.IllegalStateException: Scanner closed at java.util.Scanner.ensureOpen(Unknown Source) at java.util.Scanner.hasNext(Unknown Source) at StatsDemo.main(StatsDemo.java:48) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at edu.rice.cs.drjava.model.compiler.JavacCompiler.runCommand(JavacCompiler.java:272)
Java Code:
import java.text.DecimalFormat; //for number formatting import java.util.Scanner; //for keyboard input import java.io.*; //for using files public class StatsDemo { public static void main(String [] args) throws IOException
Assume that vehicles are going through a two-way traffic intersection. There are three types of vehicles: car, motor bikes and trucks. Generate a series of 10 random integers, between 1 and 3,inclusive.The numbers represent the type of vehicle as stated below:
NumberVehicle Category 1Car 2Motor bikes 3Trucks
Write a program, using a for loop, to count how many vehicles going through the traffic intersection are cars, motor bikes and trucks. Then, the program should print out the numbers for each vehicle category. There is no user input for this program. How do i do it so they will add up the sum of each vehicle?
The answer should be something like
Number of cars = X Number of motor bikes = Y Number of Trucks = Z
I am currently taking a class in the field. My assignment is to generate 6 unique random numbers using a "Do While" expression. I might be mistaken but doesnt the inner loop execute first and then it works its way out? With this logic I believe my code should work but then again its not.
public class DoLottery { public static void main (String args[]) { int max= 10; int random; int random2; int random3;
[code]...
I originally had output at the end but decided to comment it out to see if code would execute if I placed it every time the test was true.
I need a phonebook that allows the user to input up to 100 numbers but stop when they want to. I have the code for the array and input and output. I thought I had the do...while loop correct for asking the user if they want to input another name but its not working, even when you input "N" it still keeps going. Here's my code.
import java.util.Scanner; import java.util.ArrayList; public class PhoneEntry2 { int x; char repeat; final int maxContacts = 100; String[] pNums = new String[100];
I need to fix a program in which the user must get a three random numbers in a row. They have five chances. This is what i have so far:
public static void main(String[] args)throws IOException { // TODO code application logic here BufferedReader br=new BufferedReader(new InputStreamReader(System.in)); int num1=(int)(Math.random()*(9-0)); int num2=(int)(Math.random()*(9-0)); int num3=(int)(Math.random()*(9-0));
Prompt the user to enter two ints, firstNum and secondNum. Then print all odd numbers between firstNum and secondNum.
Here's my code-- my error is in this line: for(firstNum;firstNum<=secondNum;firstNum++)
The error is "not a statement."
import java.io.*; import java.util.*; public class ListOddNumbers { public static void main(String[] args) { Scanner keyboard= new Scanner(System.in); System.out.println("Enter your first number."); int firstNum= keyboard.nextInt();
I am trying to find 3 largest numbers in an array using a single For loop but my following code is still showing randomly sorted numbers.
public class largest3 { static int m, n, o; static int array[] = new int[100]; public static void main(String[] args) { for (int i = 0; i < 10; i++) { array[i] = (int) (Math.random() * 100);
import java.util.Scanner; public class AvgLrgSml{ public static void main(String[]args){ System.out.print("Hello there. Please enter any three numbers."); Scanner keyboard = new Scanner(System.in); double num1 = keyboard.nextDouble(); double num2 = keyboard.nextDouble();
I'm having some issues getting this code to reject negative numbers. What I'm doing wrong.
import java.util.Random; import java.util.Scanner; public class ForLoop { public static void main (String [] args) { Random randomNumber = new Random();
I'm just not noticing why it won't display the answer. I'm trying to solve this book problem......
"Write a for loop that calculates the total of the follower series of numbers:
1/30 + 2/29 + 3/28......+30/1"
Here is what I have..
public static void main(String[] args) { double total = 0; for (double a = 1, b = 30; b < 1; a++, b--) { total += (a / b); } System.out.println(total); } }
When launched, the output is 0.0. I tried changing the variables a and b to doubles but didn't change anything...
