Laurence Svekis

Laurence Svekis is a web technology enthusiast, educator, and author who has been working in the field for over 20 years. He has expertise in web development technologies, such as HTML, CSS, JavaScript, jQuery, Bootstrap, PHP, and MySQL. Svekis is a prolific course instructor on Udemy, with over 500,000 students enrolled in his courses. He has authored over 100 online courses, covering a wide range of web technologies and tools, such as Google Apps Script, WordPress, React, Node.js, Express.js, and MongoDB. His courses are known for their practical and hands-on approach, with a focus on real-world projects and examples. In addition to teaching, Svekis is also a published author, with several books to his name Svekis is passionate about empowering people with the skills and knowledge they need to succeed in the rapidly evolving field of web technology. He is committed to providing high-quality educational resources that are accessible to anyone, regardless of their background or experience level.

What is the difference between null and undefined in JavaScript?

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In JavaScript, null and undefined are both special values that represent the absence of a value. However, they have different use cases and behaviors. Here’s a detailed explanation of the difference between null and undefined: undefined: undefined is a primitive value in JavaScript. It is used to indicate the absence of an assigned value to … Read more

What are the different data types in JavaScript?

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What are the different data types in JavaScript? JavaScript has several built-in data types that are used to represent different kinds of values. Here are the different data types in JavaScript: Number:  Represents numeric values. It can be an integer or a floating-point number. For example: var age = 25; var temperature = 98.6; String:  … Read more

How do I make an HTTP request in Javascript

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In JavaScript, you can make an HTTP request using the XMLHttpRequest object or the newer fetch() function. Here’s an example of how to make an HTTP GET request using both methods: Using XMLHttpRequest: var xhr = new XMLHttpRequest(); xhr.open(“GET”, “https://api.example.com/data”, true); xhr.onreadystatechange = function() { if (xhr.readyState === 4 && xhr.status === 200) { var … Read more

Calculate the factorial of a given number

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The given code consists of two functions: FACTORIALVAL and test1. Let’s break down each function and its purpose: FACTORIALVAL(val): This function calculates the factorial value of a given number val. It first checks if the val is equal to 0. If it is, the function immediately returns 1. This is the base case of the … Read more

10 Google Sheets formulas and Videos with Example Code

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Google Sheet Formulas Formula to calculate the average of the values in a given rangeConcatenate two strings and capitalize the first letterCalculate the factorial of a given numberCount the number of occurrences of a given value in a rangeCalculate the distance between two sets of latitude and longitude coordinatesCheck if a given string is a … Read more

Calculate the distance between two sets of latitude and longitude coordinates

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The code defines a function called DISTANCE_BETWEEN that calculates the distance between two geographical coordinates on the Earth’s surface using the Haversine formula. Here’s a step-by-step breakdown of the code: Define a constant earthRadius with a value of 6371, representing the Earth’s radius in kilometers. Calculate the difference in latitude (dLat) and longitude (dLon) between … Read more

JavaScript Page element with ID auto global object

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In JavaScript, when an HTML element has an id attribute defined, it automatically becomes available as a global variable in the DOM (Document Object Model). This means you can directly access that element using its id as a variable without the need for any explicit lookups or queries. For example, if you have an HTML … Read more

AJAX coding Examples

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AJAX examples The provided code handles the submission of a form and makes an asynchronous request to a specified URL using different AJAX techniques (jQuery, Axios, Fetch, and plain JavaScript). It also displays the response received from the server. document.addEventListener(“DOMContentLoaded”, function(event) {     document.querySelector(‘input[name=”sender”]’).addEventListener(‘click’, makeRequest); }); var method = document.getElementById(‘method’); method.addEventListener(‘change’, function() {     var myForm = … Read more

How to Serialize Form data with Vanilla JavaScript

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You can use the FormData API in JavaScript. Here’s an example of how you can serialize form data: function serializeFormData(form) { var formData = new FormData(form); var serializedData = {}; for (var [name, value] of formData) { if (serializedData[name]) { if (!Array.isArray(serializedData[name])) { serializedData[name] = [serializedData[name]]; } serializedData[name].push(value); } else { serializedData[name] = value; } … Read more

NodeJS Callback explained with Code Snippet Examples

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NodeJS Callback explained with Code Snippet Examples In Node.js, callbacks are a common pattern used to handle asynchronous operations. A callback is a function that is passed as an argument to another function and gets invoked once the asynchronous operation completes or encounters an error. Let’s dive into a detailed explanation with a coding example: … Read more