Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Objects (Retired) Meet Objects Constructors

Elvi Silver Beli
Elvi Silver Beli
1,052 Points
Posted by Elvi Silver Beli
Elvi Silver Beli
1,052 Points

Whoops! java.lang.NullPointerException

i cant pass this ... what happen?

GoKart.java 
public class GoKart {
  private String mColor;


public GoKart (String color){
color=mColor;

}   

  public String getColor() {
    return mColor;
  }
}

1 Answer

Teja Tummalapalli
Teja Tummalapalli
5,592 Points
Teja Tummalapalli
Teja Tummalapalli
5,592 Points

Hi , You need to assign the passed parameter color to the private variable of the class mColor. But you are trying to do in reverse. So switch the variables in assignment operation..

public GoKart (String color){
mColor=color;
}
Elvi Silver Beli
Elvi Silver Beli
1,052 Points
Elvi Silver Beli
Elvi Silver Beli
1,052 Points

thank you so much for helping me...:)