Class Digit

java.lang.Object

Digit

All Implemented Interfaces:

Comparable<Digit>

public class Digit
extends Object
implements Comparable<Digit>

A digit whose value is always in the range 0 to 9.

Constructor Summary

Constructors

Constructor	Description
Digit(int value)	Initialize this digit to the specified value.
Digit(Digit other)	Initialize this digit by copying another digit.

Method Summary

Modifier and Type	Method	Description
static List<Digit>	allDigits()	Returns a new list containing all 10 digits (from 0 to 9).
int	compareTo(Digit other)	Compares this digit to another digit for order.
boolean	equals(Object obj)	Compares this digit to an object for equality.
static Digit	get(int i)	Returns the digit having the specified value.
int	hashCode()	Returns a hash code for this digit;
Digit	set(int value)	Sets this digit to the specified value.
String	toString()	Returns the string representation of this digit.
int	value()	Get the value of this digit

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Digit

public Digit(int value)

Initialize this digit to the specified value.

Parameters:

value - the value of this digit

Throws:

IllegalArgumentException - if value is not in the range 0 to 9

Digit

public Digit(Digit other)

Initialize this digit by copying another digit.

Parameters:

other - the digit to copy

Method Detail

value

public int value()

Get the value of this digit

Returns:

the value of this digit

get

public static Digit get(int i)

Returns the digit having the specified value.

Parameters:

i - the value of the digit

Returns:

the digit having the specified value

Throws:

IllegalArgumentException - if value is not in the range 0 to 9

set

public final Digit set(int value)

Sets this digit to the specified value.

Parameters:

value - the value of this digit

Returns:

a reference to this Digit

Throws:

IllegalArgumentException - if value is not in the range 0 to 9

allDigits

public static List<Digit> allDigits()

Returns a new list containing all 10 digits (from 0 to 9).

Returns:

a new list containing all 10 digits (from 0 to 9)

compareTo

public int compareTo(Digit other)

Compares this digit to another digit for order. The result is:

• a positive integer if the value of this digit is greater than the value of the other digit
• a negative integer if the value of this digit is less than the value of the other digit
• zero if the values of the two digits are equal

Specified by:

compareTo in interface Comparable<Digit>

Parameters:

other - a digit

Returns:

a positive integer, negative integer, or zero if the value of this digit is greater than, less than, or equal to the value of the other digit

hashCode

public int hashCode()

Returns a hash code for this digit;

Overrides:

hashCode in class Object

Returns:

a hash code for this digit

equals

public boolean equals(Object obj)

Compares this digit to an object for equality. Returns true if and only if obj is a Digit with the same value as this digit.

Overrides:

equals in class Object

Parameters:

obj - the object to compare

Returns:

true if this digit is equal to obj, false otherwise

toString

public String toString()

Returns the string representation of this digit.

Overrides:

toString in class Object

Returns:

a string representation of this digit