Answers for "js this.setstate"

how to define state in react function

import React, { useState } from 'react';

function Example() {
  // Declare a new state variable, which we'll call "count" 
  const [count, setCount] = useState(0);
  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

setState

@protected
void setState(VoidCallback fn) {
  if (_scopeKey.currentState != null) {
    _scopeKey.currentState!._routeSetState(fn);
  } else {
    // The route isn't currently visible, so we don't have to call its setState
    // method, but we do still need to call the fn callback, otherwise the state
    // in the route won't be updated!
    fn();
  }
}