-1 for a score

Question

in our class we have the decrementScore function that reduces the score for the player in the component...
decrementScore = () => {
    this.setState( prevState => ({
        score: prevState.score - 1
    }));
  };
But it will allow the score to go below zero.  I'm trying to figure out how to zero bound the function.  Everything I have tried to include and If {} else {} in the decrementScore leads to a syntax error.  How does one go about handling conditionals within state change functions?  Sorry if this is answered in later videos!

Mike Straw · Accepted Answer

Using the if statement with this.state can work, but you could run into async issues, especially when the score is close to 0, and it's being accessed by multiple players at the same time.
I used ternary operators to implement this:
javaScript
    decrementScore = () => {
        this.setState( prevState => ({
            score: prevState.score > 0 ? prevState.score - 1 : 0
        }));
    }

Federico Balzi · Answer

Hi, this is working for me: 
decrementScore = () => {
        this.setState( prev => {
            let currentScore = prev.score;
            if (currentScore > 0) {
                return {
                    score: currentScore -1
                }
            }
        })
    }

Welcome to the Treehouse Community

Looking to learn something new?

Cory Aston

Cory Aston

-1 for a score

Cory Aston

Cory Aston

2 Answers

Mike Straw

Mike Straw

Federico Balzi

Federico Balzi