What is the first thing created in this js code??

Question

React

class Application extends React.Component {
    constructor(props) {
      super(props);
      this.state = {isDangerAlertShowed: true}
      this.toggleDangerAlert = this.toggleDangerAlert.bind(this);
    }

    toggleDangerAlert() {
      this.setState(prevState => ({
        isDangerAlertShowed: !prevState.isDangerAlertShowed
      }));
    }

In this code, I don't understand this: this.toggleDangerAlert = this.toggleDangerAlert.bind(this);
After all, when this line is read, the toggleDangerAlert method has not yet been created, it is created after the constructor, while this.toggleDangerAlert = this.toggleDangerAlert.bind(this); if there is no toggleDangerAlert method yet ?

Answer 1

The method is in the prototype.
The constructor is called when an instance is created.
When you create an instance, the prototype is already defined.