personalbudget.java

Java程序设计(美) David D. Riley著 机械工业出版社 书籍配套 代码

// Figure 6.8

public class PersonalBudget  {	
	public  MoneyUSA  cashOnHand;
	public  MoneyUSA  outstandingExpenses;
	public  MoneyUSA  savings;

	public PersonalBudget()   {
		cashOnHand = new MoneyUSA(0, 0, 0, 0, 0);
		outstandingExpenses = new MoneyUSA(0, 0, 0, 0, 0);
		savings = new MoneyUSA(0, 0, 0, 0, 0);
	}
	
	/**pre:	0<=dol  and  0<=q  and  0<=di  and  0<=n  and  0<=p <br>
	 *	post:	savings is savings@pre + dol*100+q*25+di*10+n*5+p cents
	 *			consolidated into the largest possible denominations.  
	 */
	public void addToSavings(int dol, int q, int di, int n, int p) {
		savings.dollars = savings.dollars + dol;
		savings.quarters = savings.quarters + q;
		savings.dimes = savings.dimes + di;
		savings.nickels = savings.nickels + n;
		savings.pennies = savings.pennies + p;
		savings.consolidate();
	}

	/**pre:	cashonHand is constructed  and  savings is constructed <br>
	 *	post:	result = the value of cashOnHand plus savings 
	 *			consolidated into the largest possible denominations  
	 */
	public MoneyUSA totalAssets()   {
		MoneyUSA assets;
		assets = new MoneyUSA( cashOnHand.dollars + savings.dollars,
                                cashOnHand.quarters + savings.quarters,
                                cashOnHand.dimes + savings.dimes,
                                cashOnHand.nickels + savings.nickels,
                                cashOnHand.pennies + savings.pennies );
		assets.consolidate();
		return assets;
	}

	// additional methods can be included here	
}