Using “Guard Clause”

You may have seen a statement with “require” command, as an example below in ”script.js” file. First time I saw it, it threw me off. In the above example, addTwo and multiplyTwo functions are exported from “twoNumbers.js” file/module using module.exports. And then exported functions are imported into “script.js” …

On my last blog, I wrote about binding “this” to an “EventListener”. I had a similar issue with defining “this” on “forEach()”. Code below should accept an array of names (in mixed case), and return normalized names (ex. [ “anDReW”, “DAVE” ] to [ “Andrew”, “Dave” ]). However, the error…

Not knowing what “this” referring to can cause a big headache in Object Oriented Programming in JavaScript. In the example below, clicking on vote button should increase likes count (this.count) by one: However, clicking on vote button cannot increment this.count. Why is that?

In my previous blog, I wrote about Short Circuiting, using or (“||”) operator. For a quick review, Short Circuiting using or (“||”) will return the value of first true operand, or the value of the last operand if all operands are false. Short Circuiting using and (“&&”) operand will return: the value of first false operand: and (“&&”)…

The other day, I ran into code that I did not quite understood. And it looked something like below: The line 13 did not make sense to me. I understood double pipe operator (||) as logical “or” operator that I only used get either “true” or “false” Boolean value:

I was writing a code to increment “likes” count when a button is clicked and a condition is met. Simple enough…I thought. However, for some reason the count would not increment on the first click. Below is simplified code that I had: I threw in console.log(voteCount) in line 14, and…

I was reviewing javaScript .sort() method, and I got confusion. MDN Web Docs states (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort) following: If compareFunction(a, b) returns less than 0, leave a and b unchanged. If compareFunction(a, b) returns 0, leave a and b unchanged with respect to each other, but sorted with respect to all different…

I wrote a blog on Scope a couple of blogs before, and it took some time for me to understand the difference between Scope and Closure. In the example below, invoking calculator() (line 13) causes “ReferenceError: calculator if not defined”. This is due to Scope. …

Rule of thumb is all variables (const, let) must be declared before it can be used (var has slightly different rule, but we should never use var in new javaScript). Using a variable that has not been declared causes “Uncaught ReferenceError: not defined”: Using a variable that is declared later…