新的一周，新任务 - 我需要帮助的新麻烦！作业是： 写一个名为Month的类。该类应该有一个名为monthNumber的int字段，该字段包含月份的编号。例如，1月将是1，2月将是2，依此类推。该类还应该有一个名为lastMonthCreated的静态字段，该字段包含上次构造的月份数。另外，提供以下方法：
将monthNumber字段设置为1的无参数构造函数。 一个构造函数，它接受月份的数量作为参数。它应该将monthNumber字段设置为作为参数传递的值。如果传递的值小于1或大于12，则构造函数应将monthNumber设置为1。 接受月份名称的构造函数，例如“January”或“February”作为参数。它应该将monthNumber字段设置为正确的对应值。 接受int参数的setMonthNumber方法，该参数分配给monthNumber字段。如果传递的值小于1或大于12，则该方法应将monthNumber设置为1。 一个getMonthNumber方法，它返回monthNumber字段中的值。 一个getMonthName方法，它返回月份的名称。例如，如果monthNumber字段包含1，则此方法应返回“January”。 一个getLastMonthCreated方法，它返回lastMonthCreated字段中的值。 一个toString方法，它返回与getMonthName方法相同的值。 一个equals方法，它接受Month对象作为参数。如果参数对象包含与调用对象相同的数据，则此方法应返回true。否则，它应该返回false。 接受Month对象作为参数的greaterThan方法。如果调用对象的monthNumber字段大于参数的monthNumber字段，则此方法应返回true。否则，它应该返回false。 一个lessThan方法，它接受Month对象作为参数。如果调用对象的monthNumber字段小于参数的monthNumber字段，则此方法应返回true。否则，它应该返回false。 通过使用一组三个测试程序MonthDemo1.java，MonthDemo2.java和MonthDemo3.java演示Month类，可以从此分配链接下面的MonthDemo文件夹下载。
基本上我有一个很好的解决方案（希望是一个很好的解决方案），当我编译时我会遇到很多错误 - 我将它们从48降到了6.
错误：
第47行：意外类型monthNumber =（monthName [（index + 1）++]）;
^错误指向索引 - 所以我尝试创建一个名为index的变量并在使用它之前初始化，但没有改变。 必需：变量 type：value
第91行：不兼容的类型，如果（monthName = monthName [index]）
，则无法将String转换为String []
^我得到了这句话，但不知道如何更改它以获得我需要的东西。
^同一行再次出现相同错误
第92行：找不到符号返回getLastCreated;`
^我在顶部定义了这个但没有初始化 - 如果我这样做会有帮助吗？我尝试初始化为0并且为null并且出错。
93号线再次相同
基本上我正在寻找两件事，首先是关于如何处理这些错误的任何提示，以及一般来说，我是否正在使用这个，或者是否有需要改变的部分的想法让它起作用。如果您建议更改，您是否介意建议实际代码并解释原因，因为我真的很新，并希望从建议中学习而不仅仅是实施。
所有的帮助非常感谢 - 自从启动Java以来，我在这个论坛上学到了很多东西！
PS - 会改变我的方法上的情况以降低 - 只是让它们在我看上去更容易看到它们。
public class Month
{
private int monthNumber;
String[] monthName = {
"January", "Februry", "March",
"April", "May", "June", "July", "August", "September",
"October", "November", "December"
}; //Months.
int MonthNumberInt = 0;
public static String lastMonthCreated;
/**
A no-arg constructor that sets the monthNumber field to 1.
*/
public Month() {
monthNumber = 1;
}
/**
A constructor that accepts the number of the month as an argument. It
should set the monthNumber field to
the value passed as the argument. If a value less than 1 or greater than
12 is passed, the constructor
should set monthNumber to 1.
*/
public Month(int monthNumber) {
if ((monthNumber < 1) || (monthNumber > 12)) {
monthNumber = 1;
} else {
monthNumber = monthNumber;
}
}
/**
A constructor that accepts the name of the month, such as "January" or
"February" as an argument. It should
set the monthNumber field to the correct corresponding value.
*/
public String Month(String monthName[]) {
int index = 0;
monthNumber = (monthName[(index + 1)++]);
}
/**
A setMonthNumber method that accepts an int argument, which is assigned
to the monthNumber field. If a value
less than 1 or greater than 12 is passed, the method should set
monthNumber to 1.
*/
public int setMonthNumber(int monthNumberInt) {
if ((monthNumber < 1) || (monthNumber > 12)) {
return monthNumber = 1;
}
monthNumberInt = monthNumber;
}
/**
A getMonthNumber method that returns the value in the monthNumber field.
*/
public int getMonthNumber() {
return monthNumber;
}
/**
A getMonthName method that returns the name of the month. For example, if
the monthNumber field contains 1,
then this method should return "January".
*/
public String getMonthName() {
return monthName[monthNumber - 1];
}
/**
A getLastMonthCreated method that returns the value in the
lastMonthCreated field.
*/
public String getLastMonthCreated() {
for (int index = 0; index < monthName.length; index++) //Check through
the array. {
if (monthName = monthName[index]) getLastCreated = monthName[index - 1];
return getLastCreated;
}
}
/**
A toString method that returns the same value as the getMonthName method.
*/
public String toString() {
String str = "monthName: " + getMonthName();
}
/**
An equals method that accepts a Month object as an argument. If the
argument object holds the same data as the
calling object, this method should return true. Otherwise, it should
return false.
*/
public boolean Equals(Month m1) //Month needs to go here.
{
if (monthNumber == m1.getMonthNumber()) return true;
else return false;
}
/**
A greaterThan method that accepts a Month object as an argument. If the
calling object's monthNumber field
is greater than the argument's monthNumber field, this method should
return true. Otherwise, it should
return false.
*/
public boolean GreatThan(Month m1) //Month needs to go here.
{
if (monthNumber > m1.monthNumber) return true;
else return false;
}
/**
A lessThan method that accepts a Month object as an argument. If the
calling object's monthNumber field is
less than the argument's monthNumber field, this method should return
true. Otherwise, it should return
false.
*/
public boolean LesserThan(Month m1) //Month needs to go here.
{
if (monthNumber < m1.monthNumber) return true;
else return false;
}
}
demo1的
public class MonthDemo1
{
public static void main(String[] args)
{
// Use the no-arg constructor.
Month m = new Month();
System.out.println("Month " + m.getMonthNumber() +
" is " + m);
// Set the month number to the values 0 through 12
// (0 is invalid), and display the resulting month name.
for (int i = 0; i <= 12; i++)
{
m.setMonthNumber(i);
System.out.println("Month " + m.getMonthNumber() +
" is " + m);
}
}
}
DEMO 2
public class MonthDemo2
{
public static void main(String[] args)
{
// Use the 2nd constructor to create two objects.
Month m1 = new Month(10);
Month m2 = new Month(5);
System.out.println("Month " + m1.getMonthNumber() +
" is " + m1);
System.out.println("Month " + m2.getMonthNumber() +
" is " + m2);
// Test for equality.
if (m1.equals(m2))
System.out.println(m1 + " and " + m2 + " are equal.");
else
System.out.println(m1 + " and " + m2 + " are NOT equal.");
// Is m1 greater than m2?
if (m1.greaterThan(m2))
System.out.println(m1 + " is greater than " + m2);
else
System.out.println(m1 + " is NOT greater than " + m2);
// Is m1 less than m2?
if (m1.lessThan(m2))
System.out.println(m1 + " is less than " + m2);
else
System.out.println(m1 + " is NOT less than " + m2);
}
}
DEMO 3
public class MonthDemo3
{
public static void main(String[] args)
{
// Use the 3rd constructor to create three objects.
Month m1 = new Month("March");
Month m2 = new Month("December");
Month m3 = new Month("Bad Month");
System.out.println("Month " + m1.getMonthNumber() +
" is " + m1);
System.out.println("Month " + m2.getMonthNumber() +
" is " + m2);
System.out.println("Month " + m3.getMonthNumber() +
" is " + m3);
Month m4 = new Month("May");
System.out.println("The last month created" +
" is " + m4.getLastMonthCreated());
}
}
答案 0 :(得分：2)
我只能说你很困惑。您的代码存在以下几个问题：
public String Month(String monthName[])。monthNumber和MonthNumberInt。 MonthNumberInt应为monthNumberInt。Month的新实例，因为您不能每个月使用相同的实例。StackOverflow之前，代码应格式正确，以便其他人可以查看。这是重写的作品：
public class Month {
String[] monthName = { "January", "Februry", "March",
"April", "May", "June", "July", "August", "September",
"October", "November", "December" }; //Months.
int monthNumberInt = 0;
public static String lastMonthCreated;
/**
A no-arg constructor that sets the monthNumber field to 1.
*/
public Month()
{
monthNumberInt = 1;
}
/**
A constructor that accepts the number of the month as an argument. It
should set the monthNumber field to
the value passed as the argument. If a value less than 1 or greater than
12 is passed, the constructor
should set monthNumber to 1.
*/
public Month(int monthNumber)
{
if((monthNumber < 1 ) || ( monthNumber > 12)) {
this.monthNumberInt = 1;
} else {
this.monthNumberInt = monthNumber;
}
}
public Month(String monthName)
{
monthNumberInt = monthName.indexOf(monthName);
}
public int getMonthNumberInt() {
return monthNumberInt;
}
public void setMonthNumberInt(int monthNumberInt) {
this.monthNumberInt = monthNumberInt;
}
/**
A toString method that returns the same value as the getMonthName method.
*/
public String toString()
{
return "monthName: " + monthName[monthNumberInt];
}
/**
An equals method that accepts a Month object as an argument. If the
argument object holds the same data as the
calling object, this method should return true. Otherwise, it should
return false.
*/
public boolean Equals(Month m)//Month needs to go here.
{
if(this.monthNumberInt == m.getMonthNumberInt())
return true;
else
return false;
}
/**
A greaterThan method that accepts a Month object as an argument. If the
calling object's monthNumber field
is greater than the argument's monthNumber field, this method should
return true. Otherwise, it should
return false.
*/
public boolean GreatThan(Month m1)//Month needs to go here.
{
if(monthNumberInt > m1.monthNumberInt)
return true;
else
return false;
}
/**
A lessThan method that accepts a Month object as an argument. If the
calling object's monthNumber field is
less than the argument's monthNumber field, this method should return
true. Otherwise, it should return
false.
*/
public boolean LesserThan(Month m1)//Month needs to go here.
{
if(monthNumberInt < m1.monthNumberInt)
return true;
else
return false;
}
}
我测试了它：
public static void main(String[] args) {
Month m;
// Set the month number to the values 0 through 12 // (0 is invalid), and display the resulting month name.
for (int i = 0; i <12; i++) {
m = new Month();
m.setMonthNumberInt(i);
System.out.println("Month " + m.getMonthNumberInt() + " is " + m);
}
}
输出是：
Month 0 is monthName: January
Month 1 is monthName: Februry
Month 2 is monthName: March
Month 3 is monthName: April
Month 4 is monthName: May
Month 5 is monthName: June
Month 6 is monthName: July
Month 7 is monthName: August
Month 8 is monthName: September
Month 9 is monthName: October
Month 10 is monthName: November
Month 11 is monthName: December
答案 1 :(得分：0)
String[] monthName = {"January", "February",
"March", "April", "May", "June", "July",
"August", "September", "October", "November",
"December"};
Calendar cal = Calendar.getInstance();
String month = monthName[cal.get(Calendar.MONTH)];