[Functional setState] #react

functional-setState.js

import React from 'react'

// Optional import from external file
import { increaseScore } from "../stateChanges"

// outside your component class
function increaseScore (state, props) {
  return { score : state.score + 1 }
}

class User extends React.Component {
  constructor(props) {
   super(props) 
  }

  // inside your component class
  handleIncreaseScore () {
    this.setState(increaseScore)
  }

  render() {
    return (
   	  <div>User Component</div>
    ) 
  }
}