javascript

Detecting the country and region of the visiting user on the browser is certainly possible using JavaScript alone, without using any third-party geolocation service such as ipstack. The only consideration: It may not be accurate, and depend on the timezone selected by the user on their system, which can be changed. But since hardly anybody changes their system-auto-detected timezone nowadays (except for testing, which I have shown below), it is a good enough and cheap detection method for non-critical use cases.

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We know that there is no true random number. The best we get is pseudo-random number, which comes from a seed value. I was wondering if I could get a random number without using Math.random() function of JavaScript. So I developed an algorithm of my own, which is a few lines of code that works by keeping, updating, and shifting a seed array in the state. [Read More]

We have two similar JavaScript objects and are interested in finding which key(s), if any, have changed at the first level. A key in the object could hold any data type in its value, including array and object, and it could also be deeply nested. The change could mean anything, such as added, added to, removed, removed from, modified, shuffled, etc.

You may require this kind of key identification in cases where you compare the old and new states, such as previous and new filters, and figure out what exactly changed.

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Token Bucket is a rate-limiting algorithm in which there is a bucket that gets refilled at a particular rate with tokens. To perform an action, one or more tokens can be taken out or redeemed from this bucket. When there are no more tokens left, the action cannot be performed until the bucket is refilled and further tokens are available. [Read More]

Recently I came across a problem where I needed to perform two different sets of operations throughout the application for two types of users. The trouble was:

1. I needed to turn on or off an operation based on certain condition, which would only be known once the user was logged in, not at the beginning.

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In JavaScript applications with Rollbar integrated for reporting, you might see a common recurrence of the following error:

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In JavaScript applications, especially on Frontend apps, we might want to disable our console.log (or any variant of it, such as warn, info, debug, error, etc.) that we have placed for debugging throughout the application. Below are the two possible ways to do it:

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Node Package Manager, or NPM, is a defacto registry of JavaScript libraries, where anyone can create and publish a library (called package), both public and private. For publishing private packages, subscription fee is required.

In this post, we will discuss how we can host our public or private JavaScript library at Github, maintain various versions of the library using tags, and, finally, include a specific version of the library in some project and use its code.

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In this post, we will check an example of recursion with default function parameter of es6 JavaScript. Mind you, there is no benefit of doing the recursion this way. On the contrary, it is always better to write a more readable recursion algorithm within the body of the function. This is just for the sake of demonstration!

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Two new features introduced in JavaScript es6 were destructuring and spread. Combining both, along with default function parameters, we can create and use a design pattern called Destructuring and Restructuring, that is more declarative than the usual implementation. This pattern and its name come from Kyle Simpson. [Read More]