prompt js

var answer = prompt("How are you? ");var answer = prompt('What is your name?','Joe Blogg');var person = prompt("Please enter your name", "Harry Potter");

if (person != null) {
  document.getElementById("demo").innerHTML =
  "Hello " + person + "! How are you today?";
}Copyvar name = window.prompt("Enter your name: ");
alert("Your name is " + name);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;