Five cool JavaScript tricks

Fourhtyoz — Fri, 01 Nov 2024 07:28:38 +0000

Hi there!
Below you'll find 5 neart JavaScript tricks that you can start using today in your projects. Both beginners and more seasoned developers might find it interesting:

1. Debouncing Function Calls

Debouncing is a technique to limit the number of times a function is executed in response to events like scrolling. This can improve performance by ensuring that the function runs a set amount of time after the event has stopped.

function debounce(func, delay) {
    let timeoutId;
    return function(...args) {
        if (timeoutId) {
            clearTimeout(timeoutId);
        }
        timeoutId = setTimeout(() => {
            func.apply(this, args);
        }, delay);
    };
}

// Usage Example
window.addEventListener('resize', debounce(() => {
    console.log('Window resized!');
}, 500));

2. Creating a Simple Modal

You can create a simple modal dialog with just HTML and JavaScript. Here’s how you can do it:

<!-- Modal HTML -->
<div id="myModal" style="display:none; position:fixed; top:0; left:0; width:100%; height:100%; background-color:rgba(0,0,0,0.5);">
    <div style="background:#fff; margin: 15% auto; padding: 20px; width: 80%;">
        <span id="closeModal" style="cursor:pointer; float:right;">&times;</span>
        <p>This is a simple modal!</p>
    </div>
</div>

<button id="openModal">Open Modal</button>

<script>
    const modal = document.getElementById('myModal');
    const openBtn = document.getElementById('openModal');
    const closeBtn = document.getElementById('closeModal');

    openBtn.onclick = function() {
        modal.style.display = 'block';
    };

    closeBtn.onclick = function() {
        modal.style.display = 'none';
    };

    window.onclick = function(event) {
        if (event.target === modal) {
            modal.style.display = 'none';
        }
    };
</script>

3. Dynamic Property Names in Objects

You can use computed property names in object literals to create objects with dynamic keys.

const key = 'name';
const value = 'John';

const obj = {
    [key]: value,
    age: 30
};

console.log(obj); // { name: 'John', age: 30 }

4. Detecting Performance with Performance API

You can measure the performance of different parts of your code using the Performance API, which is helpful for identifying bottlenecks.

console.time("myFunction");

function myFunction() {
    for (let i = 0; i < 1e6; i++) {
        // Some time-consuming operation
    }
}

myFunction();
console.timeEnd("myFunction"); // Logs the time taken to execute `myFunction`

5. Prototypal Inheritance

You can utilize JavaScript’s prototypal inheritance to create a simple class-like structure.

function Animal(name) {
    this.name = name;
}

Animal.prototype.speak = function() {
    console.log(`${this.name} makes a noise.`);
};

function Dog(name) {
    Animal.call(this, name); // Call parent constructor
}

// Inheriting from Animal
Dog.prototype = Object.create(Animal.prototype);
Dog.prototype.constructor = Dog;

Dog.prototype.speak = function() {
    console.log(`${this.name} barks.`);
};

const dog = new Dog('Rex');
dog.speak(); // "Rex barks."

Hopefully, you've learnt something new today.