初始化包含数组的类的新对象

Question

I'm new at java, not doing well, need some help. I have a class called "RestaurantObject" and I am trying to create an object from that class in my main. I'm having a problem because one of the variables in that object is an array. I'm just really not sure what to put there.

Here is my main:

public class MyRestaurantObject {
     public static void main(String[] args) {

     RestaurantObject mcDonalds = new RestaurantObject("McDonalds", "McDonalds Menu", **WHAT GOES HERE?**);

Here is the code from my class "RestaurantObjects"

public class RestaurantObject {

private static final Object[] String = null;
private String restaurantName;
private String menu;
private String [] employees;


public RestaurantObject(String name, String menu, String [] employees){
setRestaurantName(name);
setMenu(menu);
setEmployees(employees);
}


//restaurantName
public String getRestaurantName(){
return restaurantName;
}

private void setRestaurantName(String name){
restaurantName = name;
}

//menu
public String getMenu(){
return menu;
}

private void setMenu(String menu){
this.menu = menu;
}

//employees
public String[] getEmployees(){
return employees;

}

private void setEmployees(String [] employees){
this.employees = employees;
}

}

I know I'm not doing this right. Please help!

Thank you!

Also, please correct me if any of my terminology is wrong.

Answer 1

只需在第3个参数中传递一个新的字符串数组即可。

RestaurantObject mcDonalds = new RestaurantObject("McDonalds", "McDonalds Menu", new String[] {"Value1", "Value2"});

Answer 2

I'm guessing that you haven't learned Java varargs yet, but this is a perfect case where to use them. Then you could go

public RestaurantObject(String name, String menu, String...employees) {
   setRestaurantName(name);
   setMenu(menu);
   setEmployees(employees);
}

and later,

RestaurantObject mcDonalds = new RestaurantObject(
        "McDonalds", "McDonalds Menu", "John Doe", "Jane Doe");

If you can't use or haven't learned varargs yet, @fvu version 2 is my preference.

Answer 3

Well there are two options:

1 Create the array before your create your RestaurantObject (The class should really just be called Restaurant

String[] emplArr = new String[]{ "Bob", "Alice", "Fred"};
RestaurantObject mcDonalds;
mcDonalds = new RestaurantObject("McDonalds", "McDonalds Menu", emplArr);

2 Intialize an array with a static intializer in the constructor call for RestaurantObject

RestaurantObject mcDonalds;
mcDonalds = new RestaurantObject("McDonalds", "McDonalds Menu", new String[]{ "Bob", "Alice", "Fred"});

Answer 4

You can do

RestaurantObject mcDonalds = new RestaurantObject(
    "McDonalds", "McDonalds Menu", new String[] {"John Doe", "Jane Doe"});

or

String[] employees = new String[] {"John Doe", "Jane Doe"};
RestaurantObject mcDonalds = new RestaurantObject(
    "McDonalds", "McDonalds Menu", employees);

or

String[] employees = new String[2];
employees[0] = "John Doe";
employees[1] = "Jane Doe";
RestaurantObject mcDonalds = new RestaurantObject(
    "McDonalds", "McDonalds Menu", employees);

A note regarding the latter: when you create an array like this, you have to know its size, which can be quite annoying sometimes. That's why many people will prefer to use ArrayList s which behaves more or less like an elastic array, ie it autoexpands when n item is added.