Data binding in React

Question

What I want to do is when I type some text in an input field, it should appear in another place realtime.

Below is my input;

Answer 1

I think @Richard Garside is correct.

I suggest some changes to clear even more the code.

Change this

onChange={(e) => this.update("field2", e)}

To this

onChange={this.handleOnChange}

And also, change this

this.setState({ [name]: e.target.value });

To this

this.setState({ [e.target.name]: e.target.value})

Besides, you have to add the "name" attribute to the field with a value that relates with the key on the state object.