CODEWITHSUNDEEP
java
user2926298
user2926298

Reputation: 13

the operator + is undefined for the argument type(s) Constante

I'm trying to do a sum but i always get that type error .The class OperateurBinair takes two parameters of type Constante , Constante is a class in which i create values (type = double ). 

public class Plus extends OperateurBinair {

Constante Left;
Constante Right     ;
Constante Somme ; 

Plus() {

    super();
    Left = new Constante();
    Right = new Constante();
    }

Plus(Constante x , Constante y) {

super(x,y);
Left=x;
Right=y;
}

Constante addition() {

    return Left + Right;
    }
}

Upvotes: 0

Views: 157

Answers (2)

Richard Tingle
Richard Tingle

Reputation: 17226

Constante is an object and you cannot add objects (with the exception of String, which is a special case), because the meaning of that would change from object to object, if it had a meaning at all.

Constante may have a method constante.add(otherConstante) or if it's your own class you could write one. the .add() method would most likely add whatever numberic values are contained within Constante.

Alternatively, stop using the class Constante and start using a double (or other numeric primitive) if you do not require object behaviour.

Other notes

Variable names like Left should not start with a capital letter by convention. Classes are in UpperCamelCase, variables are in lowerCamelCase.

Upvotes: 0

nhgrif
nhgrif

Reputation: 62062

Replace 

return Left + Right;

with 

return Constante(Left.getter() + Right.getter());

Where getter is the getter method for whatever value you'r actually trying to sum. This also assumes you have a constructor for Constante that takes a double argument. If not, you'll need something more like this:

Constante sum = new Constante;
sum.setter(Left.getter() + Right.getter());
return sum;

(Or just add a constructor that takes a double.)

Or alternatively, you can add a method to Constante to do the summing.

public static Constante sum(Constante addend1, Constante addend2) {
    //do whatever logic you want for summing these and return a Constante 
    //with the new value
}

Then in the class you're currently working in, you can do:

return Constante.sum(Left, Right);

Upvotes: 3

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