Sum an Array of Numbers with JavaScript
It's rare that I'm disappointed by the JavaScript language not having a function that I need. One such case was summing an array of numbers -- I was expecting Math.sum or a likewise, baked in API. Fear not -- summing an array of numbers is easy using Array.prototype.reduce!
const numbers = [1, 2, 3, 4];
const sum = numbers.reduce((a, b) => a + b, 0);
The 0 represents the starting value while with a and b, one represents the running total with the other representing the value to be added. You'll also note that using reduce prevents side effects! I'd still prefer something like Math.sum(...numbers) but a simple reduce will do!
![I’m an Impostor]()
This is the hardest thing I've ever had to write, much less admit to myself. I've written resignation letters from jobs I've loved, I've ended relationships, I've failed at a host of tasks, and let myself down in my life. All of those feelings were very...
![Vibration API]()
Many of the new APIs provided to us by browser vendors are more targeted toward the mobile user than the desktop user. One of those simple APIs the Vibration API. The Vibration API allows developers to direct the device, using JavaScript, to vibrate in...
![HTML5’s placeholder Attribute]()
HTML5 has introduced many features to the browser; some HTML-based, some in the form of JavaScript APIs, but all of them useful. One of my favorites if the introduction of the placeholder attribute to INPUT elements. The placeholder attribute shows text in a field until the...
![Create a Simple Slideshow Using MooTools]()
One excellent way to add dynamism to any website is to implement a slideshow featuring images or sliding content. Of course there are numerous slideshow plugins available but many of them can be overkill if you want to do simple slideshow without controls or events.
Initializing with 0 might not be necessary since it takes the value from the first item in the array if not provided (and then skips the first item for the rest). It’s very slightly slower to set it to 0.
Here’s what I wonder though… Suppose this were in some
math.jsmodule. Would it besum(nums)orsum(...nums)?sum([1,2,3])orsum(1,2,3)? I kinda prefer the latter.