onClick handler react code example

Example 1: 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 2: onclick react

function ActionLink() {
  function handleClick(e) {    e.preventDefault();    console.log('The link was clicked.');  }
  return (
    <a href="#" onClick={handleClick}>      Click me
    </a>
  );
}

Example 3: react button onclick

import React from 'react';

function App() {

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

export default App;

Example 4: handleClick react

class Toggle extends React.Component {
  constructor(props) {
    super(props);
    this.state = {isToggleOn: true};

    // This binding is necessary to make `this` work in the callback    this.handleClick = this.handleClick.bind(this);  }

  handleClick() {    this.setState(state => ({      isToggleOn: !state.isToggleOn    }));  }
  render() {
    return (
      <button onClick={this.handleClick}>        {this.state.isToggleOn ? 'ON' : 'OFF'}
      </button>
    );
  }
}

ReactDOM.render(
  <Toggle />,
  document.getElementById('root')
);

Example 5: handling event in jsx

//Event hadling in react
function ActionLink() {
  function handleClick(e) {
    e.preventDefault();
    console.log('The link was clicked.');
  }

  return (
    <a href="#" onClick={handleClick}>
      Click me
    </a>
  );
}

Example 6: react why onclick property function trigger without click

change:
  <button type="button" onClick={this.myFunction(argument)}> myButton </button>
  
to this: 
  <button type="button" onClick={this.myFunction.bind(this, argument)}> myButton </button>