React Notes

July 7, 2018

Functional Components

code

import React from "react";

export default () => (
  <div>
    <p>Hello Functional Component</p>
  </div>
);

Class Components

code

import React from "react";

class Counter extends React.Component {
  render() {
    return <div>Hello Class Component</div>;
  }
}

export default Counter;

Class components allow us to have component state

Component State

code

constructor() {
  super()
  this.state = { count: 0 }
}

Example: Basic Counter

code

import React, { Component } from "react";

class Counter extends Component {
  constructor() {
    super();
    this.state = {
      count: 0,
    };
  }

  render() {
    return (
      <div>
        <h1>Counter</h1>
        <p>Current Count: {this.state.count}</p>
        <button onClick={() => this.setState({ count: this.state.count + 1 })}>Plus +</button>
        <button onClick={() => this.setState({ count: this.state.count - 1 })}>Minus -</button>
      </div>
    );
  }
}

export default Counter;