javascript - TypeError: Cannont Read Property `State` of Undefined

Question

Getting the error :

TypeError: Cannot read property 'state' of undefined

I face this error when i am going to get my input state value by event onSubmit() .

onFormSubmit(event){
    event.preventDefault();
    console.log(this.state.term);
}

Answer 1

You dont have context (this is not bound to your function).

You can fix that using one of the following:

First, bind this in constructor

constructor(props) {
  super(props);
  this.onFormSubmit = this.onFormSubmit.bind(this);
}

Second, use arrow functions

onFormSubmit = (event) => {
  ...
}

Third, use autobind-decorator or the like

@boundMethod
onFormSubmit(event) {
  ...
}