React- Cannot read property 'setState' of undefined

Question

for some reason, I\'m getting the error \" React- Cannot read property \'setState\' of undefined\". So this.state is never getting updated with the values that the user inputs.

Answer 1

In these event handlers, e.target is the which triggered the event.

onChangeName(e) {
    //this.state.name = e.target.name
    this.setState({ name: e.target.name});
}

onChangePassword(e) {
    //this.state.password = e.target.name
    this.setState({ password: e.target.password });
}

You get an input's value by using its value property:

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

onChangePassword(e) {
    this.setState({password: e.target.value});
}

You also need to ensure this is bound properly, as per the commented-out code in your constructor.

---

If you give your inputs suitable name props, you replace these with a single onChange handler:

constructor(props) {
  super(props)
  // ...
  this.onChange = this.onChange.bind(this)
}

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

render() {
  // ...
  
  
  // ...
}