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Java Java Objects (Retired) Meet Objects Creating New Objects

Posted by Dushyant Garg
Dushyant Garg
772 Points

How do i Do this im too confused

please help i dont seem to understand the question

Example.java 
public class Example {

    public static void main(String[] args) {
        System.out.println("We are going to create a GoKart");
    }
}

2 Answers

Jeremy Hill
Jeremy Hill
29,567 Points
Jeremy Hill
Jeremy Hill
29,567 Points

In java, any time that you instantiate a new object you first write the class that you are creating an object from then you give it a name (usually something similar but not the same) and then you use the 'new' keyword, like this:

public class Example {

    public static void main(String[] args) {
        System.out.println("We are going to create an GoKart");

            GoKart kart = new GoKart("red");  // this line creates a new GoKart object.  I named it kart and it takes a single String argument ('red').  
            //Now we can use all of the GoKart methods on our GoKart object (kart) that we created.

    }
}
Dushyant Garg
Dushyant Garg
772 Points

Thanks for the help !!

Jeremy Hill
Jeremy Hill
29,567 Points
Jeremy Hill
Jeremy Hill
29,567 Points

In your GoKart class you added what is called a constructor that gets called every time a GoKart object gets created. This constructor basically initializes all of its member variables to what is passed in during the object instantiation. In your GoKart class your constructor should have looked something like this:

public class GoKart{

   String mColor;

   public GoKart(String color){  // this block of code is called the constructor; what distinguishes this as the constructor is that it doesn't have a return type and its name is the same as the class name. 
   //Whatever the parameters are is what needs to be passed in during object instantiation.  
     //So when you passed in a color in this challenge the constructor sets the member variable mColor to the color that you passed in.
      mColor = color;
   }

}

So if there is only one constructor with one String parameter then when you instantiate that object later it can only have exactly one String argument; if you try to pass in an additional argument it will throw an error. You can have several constructors as long as the arguments are not the same, otherwise it will confuse the compiler.