Inheritance classes (Java), explicit constructor error message -

so trying learn inheritance classes.

first created class called box calculate area of box.

then created testbox class in have created box object called fedex.

box class:

public class box {     private string boxname;      public void calculatearea(int length, int width) {         system.out.println("area of " + getboxinfo() + (length * width));     }      public box(string boxname) {         this.boxname = boxname;     }      public string getboxinfo() {         return boxname;     } } 

testbox class:

public class testbox {      public static void main(string[] args) {          box fedex = new box("fedex");         fedex.calculatearea(23, 2);     } } 

so far if run code works out fine , print screen shows area of fedex 46

so went create new class called newbox , used "extends" inherit methods class box, class used calculate volume

newbox class:

public class newbox extends box {      public void calculatevolume(int length, int width, int height) {         system.out.println("volume = " + (length * width * height));     } } 

now test created new object in testbox class called ups, testbox class looks this:

public class testbox {      public static void main(string[] args) {          box fedex = new box("fedex");         fedex.calculatearea(23, 2);          newbox ups = new newbox("ups");         ups.calculatearea(3, 2);         ups.calculatevolume(3, 2, 2);     } } 

when try run program following error message:

exception in thread "main" java.lang.error: unresolved compilation problem:      constructor newbox(string) undefined     @ day3.inheritence.testbox.main(testbox.java:10) 

i using eclipse ide.

what can fix code, , error message mean?

newbox has have constructor forwards parent class's constructor. try this:

public class newbox extends box{     public newbox(string name) {     super(name);   }    public void calculatevolume(int length, int width, int height){      system.out.println("volume = " + (length*width*height));   } }