Why is setState not working, is there an error?

Question

React

Why do I have an error in this case?

Answer 1

Add to the constructor:

// This binding is necessary to make `this` work in the callback
this.handleSearchs = this.handleSearchs.bind(this);

Source : https://reactjs.org/docs/handling-events.html
I would like to add a question to those experienced in React:
is this like a hack / crutch, or is this normal practice?

Answer 2

The function is not bound to any context. Write either an arrow function Or put a binding on the function:handleSearch = event => {}
onChane={this.handleSearch.bind(this)}