console.log() is a function in JavaScript used to print content to the console. When the script is run, the output of the console.log() statement can be seen in the console.

For example, the following code prints the statement 'Hello World!' to the console:

javascript
 
 
Copy code
console.log('Hello World!');

python
 
 
Copy code
age = int(input("What is your age? "))

HTML:

html
 
 
Copy code
<form>
  <label for="userName">Name: </label>
  <input type="text" name="userName" id="userName" />
  <input type="submit" value="Submit" />
</form>
<h1>Hello</h1>

JavaScript:

javascript
 
 
Copy code
document.querySelector('form').addEventListener('submit', (e) => {
  e.preventDefault();
  const userName = document.querySelector('#userName').value;
  document.querySelector('h1').textContent = `Hello, ${userName}`;
});

React is a JavaScript library for building user interfaces. It uses a declarative syntax which makes it easier to create interactive UIs. It is maintained by Facebook and a community of individual developers and companies. Learn more: https://reactjs.org/

Example of a React code bloc:

javascript
 
 
Copy code
function MyComponent() {
  return <div>Hello World</div>
}

javascript
 
 
Copy code
function countDecimalPlaces(number) {
  const decimalIndex = number.toString().indexOf('.');
  return decimalIndex >= 0 ? number.toString().length - decimalIndex - 1 : 0;
}

typescript
 
 
Copy code
function addNumbers(a: number, b: number): number {
    return a + b;
}

let sum: number = addNumbers(2, 4);
console.log(sum); // 6

The above example is a simple function written in TypeScript that takes two numbers as parameters and returns their sum.

You can store data in local storage using the localStorage object in JavaScript.

For example, to store an item with key of myKey and value of myValue, you can use the following code:

javascript
 
 
Copy code
localStorage.setItem('myKey', 'myValue');

You can then retrieve the value by using the key like this:

javascript
 
 
Copy code
let myValue = localStorage.getItem('myKey');

For more information, please checkout the MDN localStorage Documentation.

HTML:

html
 
 
Copy code
<div class="background-image-container"></div>

CSS:

css
 
 
Copy code
.background-image-container {
  background-image: url('background-image-url.jpg');
}

JavaScript:

javascript
 
 
Copy code
let hour = new Date().getHours();
const backgroundImageContainer = document.querySelector('.background-image-container');

if (hour > 18) {
  backgroundImageContainer.style.backgroundImage = 'url("background-image-url-after-18.jpg")';
}

javascript
 
 
Copy code
import React, { useState } from 'react';

const DropdownFilter = () => {
  const [selectedValue, setSelectedValue] = useState('');

  const handleChange = ({ target: { value } }) => {
    setSelectedValue(value);
  };

  return (
    <select value={selectedValue} onChange={handleChange}>
      <option value="example1">Example1</option>
      <option value="example2">Example2</option>
      <option value="example3">Example3</option>
    </select>
  );
};

export default DropdownFilter;

jsx
 
 
Copy code
import React, { useState } from 'react';

const DropdownFilter = () => {
  const [filter, setFilter] = useState('');

  const handleChangeFilter = event => {
    setFilter(event.target.value);
  }

  return (
    <div>
      <label htmlFor="filter">Filter: </label>
      <select
        name="filter"
        value={filter}
        onChange={handleChangeFilter}
      >
        <option value="">-- Please Select --</option>
        <option value="name">Name</option>
        <option value="date">Date</option>
        <option value="category">Category</option>
      </select>
    </div>
  )
};

export default DropdownFilter;

Using HTML, CSS and JavaScript, you can create a postcard contact form that is responsive for the user's name, email and message.

Below is an example of a postcard contact form HTML with CSS:

html
 
 
Copy code
<form action="mailto:yourname@email.com" method="POST" enctype="text/plain">
  <input type="text" name="name" placeholder="Your name" />
  <input type="text" name="email" placeholder="Your email" />
  <input type="text" name="message" placeholder="Your message" />
  <input type="submit" value="Send" />
</form>

And an example of the matching CSS:

css
 
 
Copy code
form {
  width: 60%;
  padding: 20px;
  text-align: center;
  background-color: #e2dcdf;
  margin: 0px auto;
}

input[type="text"] {
  width: 75%;
  border: none;
  padding: 10px;
  margin-bottom: 10px;
  background: #e2dcdf;
}

input[type="submit"] {
  padding: 10px;
  margin-top: 10px;
  background: #000000;
  color: #FFFFFF;
  font-size: 1em;
  font-weight: bold;
  border: none;
  width: 80%;
}

To make this form responsive, you should add a viewport meta tag and adjust the width size of the form to 100%, like so:

html
 
 
Copy code
<head>
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
</head>

<form action="mailto:yourname@email.com" method="POST" enctype="text/plain">
  <input type="text" name="name" placeholder="Your name" />
  <input type="text" name="email" placeholder="Your email" />
  <input type="text" name="message" placeholder="Your message" />
  <input type="submit" value="Send" />
</form>

css
 
 
Copy code
form {
  width: 100%;
  padding: 20px;
  text-align: center;
  background-color: #e2dcdf;
  margin: 0px auto;
}

input[type="text"] {
  width: 75%;
  border: none;
  padding: 10px;
  margin-bottom: 10px;
  background: #e2dcdf;
}

input[type="submit"] {
  padding: 10px;
  margin-top: 10px;
  background: #000000;
  color: #FFFFFF;
  font-size: 1em;
  font-weight: bold;
  border: none;
  width: 80%;
}

For more information on how to create responsive forms, check out this article, Building Responsive Contact Forms with HTML and CSS.

In JavaScript, you can use if statements to set conditional rendering based on a language property.

For example, if you want to render certain elements in the page based on the language property of 'en':

javascript
 
 
Copy code
if (language === 'en') {
  // render page elements in English
}

You can read more about using if statements in JavaScript here.

Using JavaScript, you can log the current day using the Date() function:

javascript
 
 
Copy code
const today = new Date();
console.log(today);

You can also use the toDateString() method to get the current date in the Day Mon Date format, e.g. Tue Mar 16:

javascript
 
 
Copy code
const today = new Date();
console.log(today.toDateString());

javascript
 
 
Copy code
const percentage = (num1, num2) => {
 return num1/num2*100
}
percentage(3, 10) // 30

javascript
 
 
Copy code
function recursiveFunction(parameter){
  //base condition
  if (condition) { 
    return;
  }
  //recursive case
  else { 
    //modify parameter
    parameter = update(parameter);
    //recursive call
    recursiveFunction(parameter);
  }
}

To add "copy-on-click" in JavaScript, you can use the following code:

HTML:

html
 
 
Copy code
<input type="text" id="copy-target" value="This is the text to copy on click" />
<button onclick="copyText()">Click to Copy</button>

CSS:

css
 
 
Copy code
input {
  font-size: 16px;
}
button {
  background-color: #4CAF50;
  border: none;
  color: white;
  padding: 15px 32px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
}

JavaScript:

javascript
 
 
Copy code
function copyText() {
  var text = document.getElementById("copy-target").value;
  var dummy = document.createElement("input");
  document.body.appendChild(dummy);
  dummy.setAttribute("id", "dummy_id");
  document.getElementById("dummy_id").value=text;
  dummy.select();
  document.execCommand("copy");
  document.body.removeChild(dummy);
}

When writing in JavaScript, there are a few key instances when using commas, quotes, parentheses, and brackets is necessary:

• Commas separate items in a list, e.g. var items = ["apple", "banana", "pear"]
• Double quotes should be used when working with string values, e.g. var greeting = "Hello World!"
• Parentheses are typically used when declaring functions, e.g. function multiply(x, y) { return x * y; }
• Brackets are used for defining objects and to enclose the body of a loop if statement, e.g. var hero = { name: "Dave", power: "Strength" };

For more information, including syntax formatting and other useful rules, please see the MDN JavaScript Guide.

A function is a block of organized, reusable code that is used to perform a single, related action. Functions provide better modularity for your application and a high degree of code reusing. In JavaScript, functions are first-class objects, because they can have properties and methods just like any other object. There are several ways to create a function:

• Function Declaration
• Function Expression
• Arrow Functions
• Function Constructors

Below is an example of a function declaration in JavaScript:

javascript
 
 
Copy code
// example of a function declaration
function sayHello(){
  console.log('Hello!');
}

// call the function
sayHello();

This is an example of what the output looks like when this code is run:

code
 
 
Copy code
Hello!

javascript
 
 
Copy code
function showTotalAmount(price, quantity) {
  return price * quantity;
}

// Example Usage
let price = 5;
let quantity = 2;
let result = showTotalAmount(price, quantity);
console.log(result); // 10

HTML:

html
 
 
Copy code
<div>
    <h1>Weather Widget for Spain - Current</h1>
    <div id="weather-widget">
        <div>
            <span>Location</span>
            <span id="location"></span>
        </div>
        <div>
            <span>Current Temp</span>
            <span id="temp"></span>
        </div>
        <div>
            <span>Wind Speed</span>
            <span id="wind"></span>
        </div>
        <div>
            <span>Humidity </span>
            <span id="humidity"></span>
        </div>
    </div>
</div>

CSS:

css
 
 
Copy code
#weather-widget div {
    padding: 10px;
    display: flex;
    margin-bottom: 10px;
}

JavaScript:

javascript
 
 
Copy code
// get current weather data for Spain
const endpoint = "https://api.openweathermap.org/data/2.5/weather?q=Spain&appid=YOUR_API_KEY_GOES_HERE";

// make the request
const xhr = new XMLHttpRequest();
xhr.open('GET', endpoint, true);
xhr.send();

// when the request is done
xhr.onreadystatechange = function(){
    if(xhr.readyState == 4 && xhr.status == 200){
        // parse the response
        const response = JSON.parse(xhr.responseText);

        // get values from the response     
        const location = response.name;
        const temp = response.main.temp;
        const humidity = response.main.humidity;
        const wind = response.wind.speed;

        // update the weather widget HTML elements 
        document.getElementById('location').innerHTML = location;
        document.getElementById('temp').innerHTML = temp;
        document.getElementById('humidity').innerHTML = humidity;
        document.getElementById('wind').innerHTML = wind;
    }
}

HTML

html
 
 
Copy code
<!DOCTYPE html>
<html>
  <head>
    <title>Play2Learn: Anagram Hunt</title>
  </head>
  <body>
    <h1>Anagram Hunt</h1>
    <form>
      <label>Your Guess:<input type="text" name="anagram-guess"/></label>
      <input type="submit" value="Guess"/>
    </form>
    <div id="anagram-hunt">
      <!-- This div will contain the anagram word and wrong guesses -->
    </div>
  </body>
</html>

CSS

css
 
 
Copy code
body {
  font-family: sans-serif;
  text-align: center;
}

#anagram-hunt {
  margin-top: 20px;
  padding: 20px;
}

JavaScript

js
 
 
Copy code
// The array of words to be used in Anagram Hunt
let words = ['alert', 'later', 'laser', 'resal', 'alters'];

// Initialize the game variables
let gameWord, guesses, wrongGuesses;

// Function to start the anagram game
const startGame = () => {
  // Select a random word from the array
  gameWord = words[Math.floor(Math.random() * words.length)];
  // Initialize the promises and wrong guesses
  guesses = '';
  wrongGuesses = [];
}

// When the guess form is submitted
document.querySelector('form').addEventListener('submit', (event) => {
  event.preventDefault();
  // Get the guess from the form
  let guess = document.querySelector('input').value;
  // Store and display the guess
  guesses += guess;
  let guessedLetters = guesses.split('');
  displayGuesses(guessedLetters);
  // Check if the guess is correct and reset the form
  if (gameWord === guess) {
    alert('You guessed the word!');
    startGame();
  } else {
    wrongGuesses.push(guess);
    document.querySelector('form').reset();
  }
  // Check if the game is over
  if (wrongGuesses.length >= 3) {
    alert('You lost!');
    startGame();
  }
});

// Function to display the guessed letters
const displayGuesses = (guessedLetters) => {
  let output = '';
  // Loop over the gameWord
  for (let i = 0; i < gameWord.length; i++) {
    // Check if letter is in the guessedLetters array
    if (guessedLetters.includes(gameWord[i])) {
      output += gameWord[i] + ' ';
    } else {
      output += '_ ';
    }
  }
  // Add the wrong guesses and update the anagram-hunt div
  document.querySelector('#anagram-hunt').innerHTML = output + '</br> Wrong guesses: ' + wrongGuesses;
}

// Start the game on page load
startGame();

Javascript

code
 
 
Copy code
function solveMeFirst(a,b) { 
    return a+b; 
} 

You can paste an embedded Google Map into HTML by using the Google Maps Embed API. This code snippet can be added to your HTML page to show an embedded map:

html
 
 
Copy code
<iframe
  width="600"
  height="450"
  frameborder="0" style="border:0"
  src="https://www.google.com/maps/embed/v1/place?key=<YOUR_API_KEY>&q=<YOUR_LOCATION>
  allowfullscreen>
</iframe>

The should be replaced with a valid Google Maps Embed API key, and the should be replaced with a valid string representing the location (such as an address, intersection, etc.). For more info and more detailed instructions, please check out this guide: https://developers.google.com/maps/documentation/embed/guide

You can use JavaScript to create a chart using an input range. You can therefore capture an event when the range changes, and update the chart with a function that queries the value of your desired inputs.

Here is an example using Chart.js:

javascript
 
 
Copy code
// Set range (in this case min is 0, max is 10 and starting is 5)
const range = document.getElementById("myRange");
range.min = 0;
range.max = 10;
range.value = 5;

// Listen for the change event.
range.addEventListener("input", function() {
    // Create chart when range changes.
    drawChart(range.value);
});

function drawChart(rangeValue) {
    // Use Chart.js to draw your chart with the updated rangeValue
}

Visit this tutorial to learn more.

Array.prototype.map() is a built-in JavaScript method that takes a function as an argument, takes each element of the array in order, and applies the function to create a new array from the array given. The function passed as an argument should return a value inside of the array map function so that it's included in the new array.

For example, the below code will map through an array and double each number. The return statement inside the function ensures that the new value that is calculated will be included in the new array:

javascript
 
 
Copy code
const arr = [2, 4, 6, 8];
const double = arr.map(num => {
  return num * 2;
});

console.log(double); // [4, 8, 12, 16]