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

Murilo de Melo
Murilo de Melo
14,456 Points
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
229,644 Points
Steven Parker
Steven Parker
229,644 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
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