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Seokhyun Wie
Full Stack JavaScript Techdegree Graduate 21,606 PointsWhy getHighScore has to be passed as function in App.js?
// inside the `render()` in `App.js`
<Player
name={player.name}
id={player.id}
key={player.id.toString()}
removePlayer={this.handleRemovePlayer}
score={player.score}
changeScore={this.handleScoreChange}
index={index}
isHighScore={this.getHightScore() === player.score}
/>
Other functions such as handleRemovePlayer and handleScoreChange are passed without function declaration, (). Why the getHighScore only works when it is passed with a pair of parenthesis? Because there is no parameter?
2 Answers
KRIS NIKOLAISEN
54,971 PointsWithout parentheses the function is assigned
removePlayer={this.handleRemovePlayer}
With parentheses the function is invoked and the return value of the function is used. Here the return value of the getHighScore function is compared to player.score
isHighScore={this.getHighScore() === player.score}
huhu ba
Full Stack JavaScript Techdegree Student 3,412 PointsThanks, awesome course
Seokhyun Wie
Full Stack JavaScript Techdegree Graduate 21,606 PointsSeokhyun Wie
Full Stack JavaScript Techdegree Graduate 21,606 PointsThanks KRIS NIKOLAISEN , the answer was simple and clear. So the concept is that if you want to use the function while passing it, you need to use parentheses to invoke; otherwise, remove it to assign and pass it down to child component. Did I get it clear enough? :)