add event listener to button react code example

Example 1: event listener for functional component

import React, { useEffect } from 'react';

const Component = (props) => {  
  useEffect(() => {
    window.addEventListener('scroll', handleScroll);
  });
  useEffect(() => {
    return () => {
      window.removeEventListener('scroll', handleScroll);
    };
  }, []);

  function handleScroll() {
    let scrollTop = window.scrollY;
  }


  return ()
}

Example 2: react button onclick

import React, { Component } from 'react';

class App extends Component {
  
  constructor(props) {
    super(props);
    this.sayHello = this.sayHello.bind(this);
  }

  sayHello() {
    alert('Hello!');
  }
  
  return (
    <button onClick={this.sayHello}>
      Click me!
    </button>
  );
}

export default App;

Example 3: react button onclick

<button onClick={sayHello}>Click</button>

Example 4: react event listener

onClick onContextMenu onDoubleClick onDrag onDragEnd onDragEnter onDragExit
onDragLeave onDragOver onDragStart onDrop onMouseDown onMouseEnter onMouseLeave
onMouseMove onMouseOut onMouseOver onMouseUp