created July 15, 2006; edits Nov 11, 2012; Feb 22, 2018
1. Examine the following Employee class.
class Employee implements Comparable<Employee>
{
private String firstName;
private String lastName;
private int birthYear;
String getFirstName() { return firstName; }
String getLastName() { return lastName; }
int getBirthYear() { return birthYear; }
public Employee( String f, String l, int year )
{
firstName = f; lastName = l; birthYear = year;
}
public String toString(){ finish this }
public int compareTo( Employee other ) { finish this }
}
Finish the compareTo() method
using all three of the instance variables.
Access them using the getX() methods.
Compare two employees by first looking at their last names.
If the names are different, return the value the String
method compareTo() returns with the last names.
If the names are equal, look at the first name and
return the value the String
method compareTo() returns.
If both parts of the name are equal,
return the difference of the birthYears so that
the older employee precedes the younger employee.
Test your implementation using this class:
import java.util.Arrays;
class EmployeeTester
{
public static void main ( String[] args )
{
Employee[] workers = new Employee[12];
workers[0] = new Employee( "Fred", "Adams", 1963);
workers[1] = new Employee( "John", "Adams", 1959);
workers[2] = new Employee( "Elmer", "Adams", 1976);
workers[3] = new Employee( "Nancy", "Devon", 1963);
workers[4] = new Employee( "Andrew", "Lewis", 1983);
workers[5] = new Employee( "Douglas", "Page", 1981);
workers[6] = new Employee( "Donald", "Wolder", 1963);
workers[7] = new Employee( "Henry", "Wolder", 1972);
workers[8] = new Employee( "Robert", "Wolder", 1959);
workers[9] = new Employee( "Howard", "Cohen", 1933);
workers[10] = new Employee( "Howard", "Cohen", 1958);
workers[11] = new Employee( "Donald", "Rice", 1935);
Arrays.sort( workers );
for ( int j=0; j<workers.length; j++ )
System.out.println( workers[j].toString() );
}
}
2. Examine the following Diamond class.
class Diamond implements Comparable<Diamond>
{
private String stockNumber;
private int carot; /* size of the diamond */
private String clarity; /* clarity grade of the diamond */
private char color; /* color grade D-Z */
private String cut; /* name of the cut */
String getStock() { return stockNumber; }
double getCarot() { return carot; }
String getClarity() { return clarity; }
char getColor() { return color; }
String getCut() { return cut; }
public Diamond( String s, double car, String clar, char col, String ct )
{
stockNumber = s; carot = car; clarity = clar; color = col; cut = ct;
}
public String toString(){ finish this }
public int compareTo( Diamond other ) { finish this }
}
The size of a diamond is measured in carets, usually less than 5.0.
The clarity grade of a diamond is a code, FL, IF, VVS1, VVS2, VS1, VS2, SI1, SI2, I1, I2, I3. The best is FL (flawless), I3 is the worst.
The color grade is a one letter code, D through Z. D is the best, Z is the worst. The cut is the name of the pattern the diamond has been cut into.
Finish the toString() and the compareTo() methods.
Write compareTo() so that diamonds are ordered first by caret,
then by clarity OR color, whichever is better for the particular diamond.
Do this by converting the codes to numbers.
Since there are 23 grades of color, but only 11 grades of clarity,
stretch the clarity scale so it is comparable to the color scale.
Write compareTo() so that better diamonds are to the left
of poor diamonds. This means that
goodDiamond.compareTo( poorDiamond )returns a negative value. Notice that large caret diamonds will appear first on the list, the reverse of the usual order for numbers.
Use this testing class:
import java.util.Arrays;
class DiamondTester
{
public static void main ( String[] args )
{
Diamond[] stones = new Diamond[16];
stones[0] = new Diamond( "A1023", 1.0, "VS1", 'F', "brilliant");
stones[1] = new Diamond( "A5911", 1.1, "VVS2", 'G', "rose");
stones[2] = new Diamond( "C5427", 1.0, "VS1", 'D', "princess");
stones[3] = new Diamond( "D8307", 1.6, "SI1", 'H', "brilliant");
stones[4] = new Diamond( "B4825", 0.3, "I1", 'D', "rose");
stones[5] = new Diamond( "A1844", 2.1, "VS2", 'D', "lozenge");
stones[6] = new Diamond( "A3747", 3.1, "SI2", 'W', "baguette");
stones[7] = new Diamond( "E6393", 2.3, "VS2", 'I', "brilliant");
stones[8] = new Diamond( "C5619", 2.8, "VVS1", 'E', "pear");
stones[9] = new Diamond( "E8348", 1.4, "VS2", 'G', "brilliant");
stones[10] = new Diamond( "D2381", 1.7, "I3", 'G', "brilliant");
stones[11] = new Diamond( "C9253", 1.3, "VS2", 'H', "baguette");
stones[12] = new Diamond( "G3459", 2.1, "VS2", 'H', "rose");
stones[13] = new Diamond( "B3598", 2.4, "VVS2", 'D', "pear");
stones[14] = new Diamond( "D9836", 2.8, "IF", 'E', "princess");
stones[15] = new Diamond( "E1046", 2.2, "FL", 'E', "rose");
Arrays.sort( stones );
for ( int j=0; j<stones.length; j++ )
System.out.println( stones[j].toString() );
}
}
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