Need help with homework... 1

[GT500FOMOCO]

I have always had problems with the % operator. I have to write a program that uses it to determin if a number entered is a multiple of 5. Here is my code:

public class Tasty {

public static void main(String[] args) {
ConsoleReader keyboard = new ConsoleReader(System.in);

String menu = "Number Item Price"
+ "\n-------------------------"
+ "\n [1] Snickers 65"
+ "\n [2] Chips 45"
+ "\n [3] Donuts 85"
+ "\n [4] Crackers 50"
+ "\n [5] Kit Kat 65"
+ "\n [6] Gum 35"
+ "\n\nEnter an item number: ";

System.out.print("Welcome to Tasty Treats vending machine."
+ "\n\nDeposit some money: "
String test = keyboard.readLine();
int pay = Integer.parseInt(test);

if (test.substring(test.length() - 1, test.length()).equals("0&quot) {
System.out.print(menu);
int choice = keyboard.readInt();

if (choice == 1) {
if (pay >= 65) {
System.out.print("\nHere's your Tasty Snickers and "
+ (pay - 65) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Snickers.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}

if (choice == 2) {
if (pay >= 45) {
System.out.print("\nHere's your Tasty Chips and "
+ (pay - 45) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Chips.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}

if (choice == 3) {
if (pay >= 85) {
System.out.print("\nHere's your Tasty Donuts and "
+ (pay - 85) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Donuts.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}

if (choice == 4) {
if (pay >= 50) {
System.out.print("\nHere's your Tasty Crackers and "
+ (pay - 50) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Crackers.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}

if (choice == 5) {
if (pay >= 45) {
System.out.print("\nHere's your Tasty Kit Kat and "
+ (pay - 45) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Kit Kat.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}

if (choice == 6) {
if (pay >= 35) {
System.out.print("\nHere's your Tasty Gum and "
+ (pay - 35) + " cents in change. "
+ "\nGood-bye from Tasty Treats!"
}

else {
System.out.print("\nYou have not entered enough "
+ "money for Tasty Gum.\nI am returning your "
+ pay + " cents.\nGood-bye from Tasty Treats!"
}
}
}

else {
System.out.print("\nSorry, I cannot accept pennies."
+ "\nI am returning your " + pay + " cents."
+ "\nGood-bye from Tasty Treats!\n\n\n"
}
}
}

Please help me. Also, I'd perfer that you'd do so without directly giving me the answer. It would help my comprehension of the material. "and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy

 

[wushutwist]

Modulus (%) is easy. It just returns the remainder of a division operation. Remember remainders? Those things everybody hated in the third grade because they screwed up what was sure to be an easy calculation.

Simply put, to determine if a number is a multiple of 5 all you need to do is to get the number modulus 5. If the resulting remainder is 0 then it is a multiple, if not then no. Simple example:

int x = 12;
if (x%5 == 0) {
  /* Multiple of 5 */
}
else {
  /* Not a multiple of 5 */
}

I didn't look at the rest of the code so I am not going to comment on it.

 

[GT500FOMOCO]

Thanks, whatever idiot tried to answer my question at the Sun forum just confused me. Thanks for the help. "and everything under the sun is in tune
but the sun is eclipsed by the moon." --Pink Floyd: Eclipse

"I'm going to spend eternity
reinstalling Windows." --Reinstalling Windows: by some British guy