Yesterday when we were on our way home, my girlfriend pointed out the window and said, "Look, look there in the background." I couldn't see at the beginning what she was talking about, but then the amazing Bernese Alps were on full display in the background. I quickly snapped this shot with my phone, which you can see in the picture above. Really nice!Amazing Bernese Alps in the Background
Yesterday when we were on our way home, my girlfriend pointed out the window and said, "Look, look there in the background." I couldn't see at the beginning what she was talking about, but then the amazing Bernese Alps were on full display in the background. I quickly snapped this shot with my phone, which you can see in the picture above. Really nice!Map, Filter and Reduce in JS
JavaScript Fundamentals
JavaScript is a high-level, dynamic, and interpreted programming language. It is one of the core technologies of the World Wide Web, alongside HTML and CSS. JavaScript allows developers to make web pages interactive, enabling features such as dynamic content updates, form validations, and complex user interfaces.
Key Concepts
Variables and Data Types
JavaScript is dynamically typed, meaning you do not need to explicitly declare the data type of a variable. The primary data types include:
- String: Textual data (e.g.,
"Hello World"). - Number: Numeric data (e.g.,
10,3.14). - Boolean: Logical data (
trueorfalse). - Object: Complex data structures (e.g.,
{ key: value }). - Array: Ordered lists of values (e.g.,
[1, 2, 3]).
Declaration Keywords:
var: Older way to declare variables (function-scoped).let: Used for variables that might be reassigned (block-scoped).const: Used for constants—variables whose value cannot be reassigned (block-scoped).
Functions
Functions are blocks of reusable code designed to perform a specific task. They help organize code and prevent repetition.
// Function declaration
function greet(name) {
return "Hello, " + name + "!";
}
// Arrow function (modern syntax)
const calculateArea = (width, height) => {
return width * height;
};
console.log(greet("Alice"));
console.log(calculateArea(5, 10));
Control Flow
Control flow statements determine the order in which code is executed.
- Conditionals (
if/else if/else): Execute code blocks based on whether a condition evaluates totrueorfalse. - Loops (
for,while): Execute a block of code repeatedly until a specified condition is met.
// For loop example
for (let i = 0; i < 5; i++) {
console.log("Count: " + i);
}
// While loop example
let count = 0;
while (count < 3) {
console.log("Still counting...");
count++;
}
Working with the DOM (Document Object Model)
The DOM is the programming interface for HTML and XML documents. JavaScript uses the DOM to read, modify, and manipulate the structure and content of a web page.
Selecting Elements
You can select HTML elements using methods like getElementById, querySelector, and querySelectorAll.
// Selects the element with the ID 'main-heading'
const heading = document.getElementById('main-heading');
// Selects the first element that matches the CSS selector '.card'
const firstCard = document.querySelector('.card');
// Selects all elements that match the CSS selector '.card'
const allCards = document.querySelectorAll('.card');
Manipulating Content and Styles
Once an element is selected, you can change its content or styling.
// Changing text content
heading.textContent = "Welcome to JavaScript!";
// Changing HTML content (use with caution due to XSS risks)
heading.innerHTML = "Welcome! <strong>Learn More</strong>";
// Changing CSS styles
firstCard.style.backgroundColor = 'lightblue';
Handling Events
Event listeners allow your JavaScript code to respond to user actions, such as clicks, key presses, or mouse movements.
const button = document.getElementById('myButton');
// Attaches a function to run when the button is clicked
button.addEventListener('click', () => {
alert('Button was clicked!');
});
Asynchronous JavaScript
Many operations in web development, such as fetching data from an API or setting a timer, do not complete instantly. These are asynchronous operations. JavaScript handles these using mechanisms like Promises and async/await.
Fetching Data (API Calls)
The fetch() API is the modern way to make HTTP requests.
async function fetchUserData(userId) {
try {
// The 'await' keyword pauses execution until the Promise resolves
const response = await fetch(`https://api.example.com/users/${userId}`);
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
const data = await response.json();
console.log("User data:", data);
return data;
} catch (error) {
console.error("Could not fetch user data:", error);
}
}
// Example usage:
fetchUser(1);
Summary of Key Concepts
| Concept | Purpose | Example |
|---|---|---|
| DOM Manipulation | Changing the structure, content, or style of an HTML page. | element.innerHTML = 'New Content'; |
| Event Handling | Responding to user actions (clicks, key presses, etc.). | button.addEventListener('click', handler); |
| Asynchronous JS | Handling operations that take time (network requests) without freezing the page. | fetch() or async/await |
| Scope | Determining where variables are accessible within the code. | let (block scope) vs. var (function scope) |
Heatwave in Europe
I recently had the pleasure of visiting Cubelles, a beautiful Catalan coastal town near Barcelona. I hit the jackpot when I found an apartment right on the beach! Spending my time there was pure bliss; almost every day was spent soaking up the sea and refreshing myself with waves.
But every time I watch the news, I realize that I was lucky to spend my days there during the heat wave that is hitting Europe. There are roaring fires in many places in southern Europe, and, on the other hand, places where the summer is not particularly strong, like the UK, are experiencing record temperatures.
No comments. The climate change problem is already here :/
Back in Berlin
A few days ago I had the opportunity to visit Berlin again and I spent some very pleasant days in the company of my dear friend C. In those days I remembered why the German capital is one of my favorite cities in Europe, and although I am satisfied with my life at the moment, I will always miss that very interesting place!
One of the things I was always curious about before leaving Berlin was what had happened with the famous Humboldt Forum. I remember the first time I visited that space in 2015: at that time it was a temporary construction, created by the Humboldt foundation, that served as an exhibition space and viewing platform for the Berlin Palace - Humboldt Forum reconstruction project.
Well 7 years later, this project is finished and the palace is back to its former glory (at least the exterior facade) and it has some interesting exhibitions inside. Above you can find a picture of how it looks nowadays. Bis (hoffentlich) bald, Berlin
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