Why is this lost?

Question

React

Greetings!
I'm losing this in the componentDidMount event. Broke my whole head. I thought that I understand the call context, but I don't see it. Already just copying examples from the Internet, there are working options. There is no this anyway.
Please tell me, maybe I'm just stupid?

componentDidMount = () => {
     const myHeaders = new Headers({
      "Content-Type": "application/json",
      Accept: "application/json"
    })

    fetch("http://localhost:3000/bookmarks.json", {
      headers: myHeaders,

    })
      .then(response => {
        console.log(response);
        return response.json();
      })
      .then(data => {
        console.log(data);
        this.setState({ data });
      })

  }

Answer 1

Here is a good answer to the question why this is lost : https://stackoverflow.com/questions/24785238/this-...
To make it work, you need to save the context in the old way: and then refer to self when calling setState. The working code looks like this:var self = this

componentDidMount() {
        const myHeaders = new Headers({
            "Content-Type": "application/json",
            Accept: "application/json"
        })

        var self = this

        fetch("https://jsonplaceholder.typicode.com/todos/1", { // ваш URL
            headers: myHeaders,
        }).then(response => {
            return response.json();
        }).then(data => {
            self.setState({ data });
        })
    }