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JavaScript Object-Oriented JavaScript: Challenge Building Constructor Methods and Generating Objects createTokens() Method Solution

Posted by Murilo de Melo
Murilo de Melo
14,456 Points

Why does the new Token in Player accepts 2 arguments, 'i' and 'this', if the token constructor has no parameters?

The Token constructor in the class Token has no parameters: 

constructor() {
        this.owner = owner; 
        this.id = `token-${index}-${owner.id}`; 
        this.dropped = false; 
 }

But within the for-loop in the class Player, the statement that creates a new Token pass two arguments: 

for (let i = 0; i < num; i++) {
            let token = new Token(i, this); 
            tokens.push(token);
}

The reason was not clear to me. Shouldn't it return an error in this case or shouldn't we rather specify the constructor with these two parameters?

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

At the bottom of the Token Properties Solution video page, in the "Teacher's Notes" tab, there is a "Code Correction" with a revised constructor definition for the Token object. It includes this line:

    constructor(index, owner){

And without the fix, I would expect to get an error in the console like this: "ReferenceError: owner is not defined".

Murilo de Melo
Murilo de Melo
14,456 Points

Thank you Steven, I should have checked that. This helps me not to forget to do that.

Regards

Murilo