KeyPadLock

Question

Hi, I have to write java code for a KeyPadLock class I need some help with the the variable declarations and a constructors
First I'm assigning elements to one of my arrays which hold the secret Code is this Ok?
Second I have to initialize it but I'm not sure how.
PS I will put the instructions in the bottom in case some one can see what I'm doing wrong
This is what i have:
public class KeyPadLock {
private boolean isOpen; // true means lock is open; false means closed
private int[] secretCode = {2, 3, 4, 5,}; // the lock's code (a sequence of digits)
private int[] red; // most recently entered digits
private boolean match = true; // to compare if secretCode to red
public KeyPadLock(int[] code) {
          red = new int [code.length];
          int i = 0;
          while (i <= red.length){
          red[i] = code;
          i = i + 1;
/** Constructs a KeyPadLock object having the code specified by the
* parameter.
* @param code an array storing the constructed lock's code
* (i.e., the sequence of digits needed to open it), stored
* one digit per element.
* @pre for all i in range 0 .. code.length - 1, 0 <= code[i] < 10
* @post The newly-constructed lock has as its code the sequence of digits
* given by code[] and its "memory" of digits entered at the keypad
* indicates that no digits have ever been entered.
Edited by: dchjava on Oct 19, 2008 3:16 PM

Answer 1

Hi,
I have worked developing my KeyPadLock class, after talking to my Professor, I realized that in my constructor I have to initialize the secretCode array and the red array, which I did. I think! I also remove one of my declaration fields (the boolean match) since I don't really need it. The program is compiling, but I still have one error in one of my methods, which Opens the KeyPadLock, the problem is that I need to implement an if statement and I'm not sure how, could I get some help with this method:
public void open() { 
          int i = 0;
          while (i != secretCode.length && secretCode[i] == red) {
          i = i + 1;
          if (i = red.lenght){
          isOpen;
          else {}
Also, here is my whole class in case it helps:
public class KeyPadLock {
private boolean isOpen; // true means lock is open; false means closed
private int[] secretCode; // the lock's code (a sequence of digits)
private int[] red; // most recently entered digits
/* c o n s t r u c t o r s */
public KeyPadLock(int[] code) {
          secretCode = new int[code.length];
          int i = 0;
          while (i < secretCode.length){
          secretCode[i] = code[i];
          i = i + 1;
          red = new int[code.length];
          int i = 0;
          while (i < red.length){
          red[i] = code[i];
          i = i + 1;
/** Reports whether or not the lock is currently open.
* @pre none
* @return true if the lock is open, false otherwise
public boolean isOpen() {
          return isOpen;
/* m u t a t o r s */
/** Records the entering of a digit on the keypad.
* @pre 0 <= digit < 10
* @post If isOpen(), the digit entered is ignored.
* Otherwise it has been recorded as the latest digit entered
* on the keypad.
public void enterDigit(int digit) {
          red[i] = dgit;
          for (int i = 0; i != red.length-1; i++){
          red[i] = red[i + 1];
          red[red.lenght] = digit;
/** Attempt to open the lock.
* @pre none
* @post If the lock was already open or if the most recently entered
* digits match the lock's code, the lock is now open.
* Otherwise, it remains closed. Nothing else about the lock
* has changed.
public void open() { 
          int i = 0;
          while (i != secretCode.length && secretCode[i] == red[i]) {
          i = i + 1;
          if (i = red.lenght){
          isOpen;
          else {}
/** Close the lock.
* @pre none
* @post !isOpen(). Nothing else about the lock has changed.
public void close() {
          isOpen = false;