employeearray.java

ssd3PQ6的答案

/**
 * This class contains methods to process arrays of {@link Employee} objects.
 * 
 * @author Wang Yunsheng
 * @version 1.0.0
 * @see Employee
 */
public class EmployeeArray {

	/**
	 * Creates an array with three objects of class {@link Employee}.
	 * <p>
	 * The first element of the array is the object <code>first</code>, the
	 * second element of the array is the object <code>second</code>, and the
	 * third element of the array is the object <code>third</code>.
	 * </p>
	 * 
	 * @param first
	 *            a {@link Employee} object.
	 * @param second
	 *            a {@link Employee} object.
	 * @param third
	 *            a {@link Employee} object.
	 * @return an array with the objects <code>first</code>,
	 *         <code>second</code>, and <code>third</code>.
	 */
	public static Employee[] makeArray(Employee first, Employee second,
			Employee third) {

		/* PLACE YOUR CODE HERE */
		Employee[] array = new Employee[3];

		array[0] = first;
		array[1] = second;
		array[2] = third;

		return array; // REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Creates a new array from the specified array of {@link Employee} objects.
	 * <p>
	 * The elements in the new array have the same order as those in the
	 * specified array.
	 * </p>
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @return a <i>new</i> array of the objects in the specified array.
	 */
	public static Employee[] copyArray(Employee[] array) {

		/* PLACE YOUR CODE HERE */
		Employee[] a = new Employee[array.length];

		if (array == null) {

			return null;
		} else {
			
			for (int i = 0; i < array.length; i++) {

				a[i] = array[i];
			}
		}

		return a;
		// REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Returns the {@link Employee} object with the specified ID.
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @param id
	 *            an employee ID.
	 * @return The {@link Employee} object with the specifed ID. Returns
	 *         <code>null</code> if there are no employees in the specified
	 *         array with the specifed ID.
	 */
	public static Employee getEmployee(Employee[] array, int id) {

		/* PLACE YOUR CODE HERE */
		for (int i = 0; i < array.length; i++) {

			if (array[i].getId() == id) {

				return array[i];
			}
		}

		return null;
		// REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Returns the number of employees whose salary is higher than the specified
	 * dollar amount.
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @param amount
	 *            a dollar amount.
	 * @return the number of employees whose salary is higher than the specified
	 *         dollar amount.
	 */
	public static int countHigherSalaries(Employee[] array, double amount) {

		/* PLACE YOUR CODE HERE */
		int num = 0;

		for (int i = 0; i < array.length; i++) {

			if (array[i].getSalary() > amount)

				num++;
		}

		return num; // REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Returns the sum of the salaries of the employees in the specified array.
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @return the sum of the salaries of the employees in the specified array.
	 */
	public static double sumSalaries(Employee[] array) {

		/* PLACE YOUR CODE HERE */
		double sum = 0.0;

		for (int i = 0; i < array.length; i++) {

			sum += array[i].getSalary();
		}

		return sum; // REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Obtains the highest salary in the specified array.
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @return the highest salary in the specified array.
	 */
	public static double getHighestSalary(Employee[] array) {

		/* PLACE YOUR CODE HERE */
		double highestSalary = 0.0;

		for (int i = 0; i < array.length; i++) {

			if (array[i].getSalary() > highestSalary)

				highestSalary = array[i].getSalary();
		}

		return highestSalary; // REMOVE; USED SO THIS FILE COMPILES
	}

	/**
	 * Increases the salary of every employee in the specified array by the
	 * specified amount.
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 */
	public static void increaseAll(Employee[] array, double amount) {

		/* PLACE YOUR CODE HERE */
		for (int i = 0; i < array.length; i++) {

			array[i].setSalary(array[i].getSalary() + amount);
		}
	}

	/**
	 * Returns a string representation of the specified {@link Employee} array.
	 * <p>
	 * Uses the method <code>toString</code> in class <code>Employee</code>
	 * to obtain the string representation of each object in the array.
	 * </p>
	 * A new line character ( \n ) separates the string representations of each
	 * <code>Employee</code> object. For example:
	 * </p>
	 * 
	 * <pre>
	 *  Employee[102,Mary Jones,68250.0]\n
	 *  Employee[101,Joe Smith,36000.0]\n
	 *  Employee[103,Richard Wong,92175.0]
	 * </pre>
	 * 
	 * <p>
	 * Note that the string returned does <i>not</i> end with a new line
	 * character (\n).
	 * </p>
	 * <p>
	 * This method assumes that every element in the specified array contains a
	 * valid reference to an <code>Employee</code> object.
	 * </p>
	 * 
	 * @param array
	 *            an array that contains objects of class {@link Employee}.
	 * @return the string representation of the specified array
	 */
	public static String displayAll(Employee[] array) {

		/* PLACE YOUR CODE HERE */
		String arrayList = new String();

		if (array == null) {

			return "";
		} else {
			for (int i = 0; i < array.length; i++) {

				if (i != array.length - 1) {

					arrayList = arrayList + array[i].toString() + "\n";
				} else
					
					arrayList = arrayList + array[array.length - 1].toString();			
			}
			
			return arrayList;
		}
		// REMOVE; USED SO THIS FILE COMPILES
	}
	
}