JavaScript is no doubt one of the coolest languages in the world and is gaining more and more popularity day by day. So the developer community has found some tricks and tips after using JS for quite a while now. Today I will share 8 Tips & Tricks With You!
So let's get started
Functional Inheritance
Functional inheritance is the process of receiving features by applying an augmenting function to an object instance. The function supplies a closure scope which you can use to keep some data private. The augmenting function uses dynamic object extension to extend the object instance with new properties and methods.
They look like:
// Base function
function Drinks(data) {
var that = {}; // Create an empty object
that.name = data.name; // Add it a "name" property
return that; // Return the object
};
// Fuction which inherits from the base function
function Coffee(data) {
// Create the Drinks object
var that = Drinks(data);
// Extend base object
that.giveName = function() {
return 'This is ' + that.name;
};
return that;
};
// Usage
var firstCoffee = Coffee({ name: 'Cappuccino' });
console.log(firstCoffee.giveName());
// Output: "This is Cappuccino"
Credits to @loverajoel for explaining this topic in depth here - Functional Inheritance on JS Tips which I've paraphrased above
.map() Substitute
.map()
also has a substitute that we can use which is .from()
:
let dogs = [
{ name: βRioβ, age: 2 },
{ name: βMacβ, age: 3 },
{ name: βBrunoβ, age: 5 },
{ name: βJucasβ, age: 10 },
{ name: βFurrβ, age: 8 },
{ name: βBluβ, age: 7 },
]
let dogsNames = Array.from(dogs, ({name}) => name);
console.log(dogsNames); // returns [βRioβ, βMacβ, βBrunoβ, βJucasβ, βFurrβ, βBluβ]
Number to string/string to number
Usually, to convert a string to a number, we use something like this:
let num = 4
let newNum = num.toString();
and to convert a string to a number, we use:
let num = "4"
let stringNumber = Number(num);
but what we can use to code fast is:
let num = 15;
let numString = num + ""; // number to string
let stringNum = +s; // string to number
Using length to resize and emptying an array
In javascript, we can override a built-in method called length
and assign it a value of our choice.
Let's look at an example:
let array_values = [1, 2, 3, 4, 5, 6, 7, 8];
console.log(array_values.length);
// 8
array_values.length = 5;
console.log(array_values.length);
// 5
console.log(array_values);
// [1, 2, 3, 4, 5]
It can also be used in emptying an array, like this:
let array_values = [1, 2, 3, 4, 5, 6, 7,8];
console.log(array_values.length);
// 8
array_values.length = 0;
console.log(array_values.length);
// 0
console.log(array_values);
// []
Swap Values with Array Destructuring.
The destructuring assignment syntax is a JavaScript expression that makes it possible to unpack values from arrays, or properties from objects, into distinct variables. We can also use that to swap values fast, like this:
let a = 1, b = 2
[a, b] = [b, a]
console.log(a) // result -> 2
console.log(b) // result -> 1
Remove duplicates from an Array
This trick is pretty simple. Let's say, I made an array that is containing numbers, strings, and booleans, but the values are repeating themselves more than once and I want to remove the duplicates. So what I can do is:
const array = [1, 3, 2, 3, 2, 1, true, false, true, 'Kio', 2, 3];
const filteredArray = [...new Set(array)];
console.log(filteredArray) // [1, 3, 2, true, false, "Kio"]
Short For Loop
You can write less code for a loop like this:
const names = ["Kio", "Rio", "Mac"];
// Long Version
for (let i = 0; i < names.length; i++) {
const name = names[i];
console.log(name);
}
// Short Version
for (let name of names) console.log(name);
Performance
In JS you can also get the time that the code was executed in like Google does:
It looks like this:
const firstTime = performance.now();
something();
const secondTime = performance.now();
console.log(`The something function took ${secondTime - firstTime} milliseconds.`);
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Thank you very much for reading this article.
Comment any tricks & tips you know!
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Oldest comments (80)
can you please remove the CSS tag since this post is not about CSS? thanks
Ya sorry actually I wrote it before because I wanted to create a CSS post π thanks for the reminder
awesome bro, thanks for sharing
Welcome Bro!! π
Thanks for sharing Garvit! About your first topic, Functional Inheritance, I don't actually agree with what you've said. Since the idea is to hide the object within a function, it kinda works, BUT, that's totally different from the concept of 'private' as data encapsulation. You can still get the object and do whatever you want. All that you doing there is hiding an object inside another, and then retrieving it. Also, be careful when using 'var', especially when talking about concepts like hoisting and closures. Your variables were actually globally scoped and their memory will not be immediatly freed after using that function.
Thanks For Sharing The Tip! Noted!
Really nice tips.
Question : what is the best option between using performance.now() and console.time() π€
I usually use
performance.now()
so I would recommend that butconsole.time()
is also good!!console.time
will be limited to output in console, hence it is more suitable for temporary debugging/test situations.Any other cases I'd use
performance.now
, like displaying time in html, sending to backend etc.Good to know thanks for this tip ππ
Map an array without .map()
Pick one. You can't say one is difficult and complicated and nobody will understand it.
And the other one is surprising, rarely taught or known but way easier to understand?
Actually, I really like that method and it is way easier than
.map()
, that's why I recommended that, but noted! Thanks for reading the articlePlease explain how your method is "way easier than .map()"?
I just don't understand your thinking here, the concepts are exactly the same, the syntax is almost exactly the same (actually longer), and you're introducing a somewhat unfamiliar syntax to most to achieve something that everyone likely understands already with .map().
thanks for sharing Garvit!
welcome bro!
Great, Garvit! It's always great to know the language so well and bring about these unconventional ways to solve problems. However, it's always recommended to write code that is self-explanatory. And, I find majority of these tricks to be confusing (to an average eye). Use them when you really have to and leave a comment to make your intention clear.
Noted! and thanks for reading the article!
On that note β which I completely agree with β it's interesting how readable this is
Array.from(dogs)
compared todogs.map()
if map wasn't so widely adopted :)On that note, I'd love to see how performant
Array.from()
is compared to.map()
that I know doesn't perform very wellNow you've inspired a more ambitious project. Building a custom standalone performance measurement tool for Javascript.
It could be something similar to Runkit, but strictly for benchmarking the various methods and approaches to the same end goal. Like which is faster?
OR
π€π€π€
I can tell you for sure that the for loop is way more performant than map. But if you do compare everything, I'm definitely interested to read.
The problem with JavaScript is that.... itβs not taught βin contextβ, itβs mainly always a βconsole.logβ that is used for the answer, instead of truly implementing it into real examples.... itβs been tough for me to learn it
Ya
Make projects to learn it! Helps a lot!!!
Liquid syntax error: Tag '{%' was not properly terminated with regexp: /\%\}/
This title makes it seem like these are tips and tricks worthwhile to use that are not that popular but extremely useful.
Most of these tips are actually well known among JS developers and aren't ones "That No One Teaches", such as the performance tip, the short for loop, using sets to remove duplicates from arrays, and swapping values with destructuring. The only ones that aren't as known are the first couple, which don't seem to be that useful.
Sorry, if that sounds rude because that isn't my intention. I am just trying to point out that most of these tips are either well known or not useful and the title is pretty misleading then.
Noted
You're right and I like your avatarπ
Thanks! I donβt remember how I created that
Great article. I'm particularly fond of the map without map.
Ya I use that at often nowadays
Thanks for sharing Garvit
It seems a typo on Map an array without .map(), it should return dogsNames rather than friendsNames.
Noted! Thanks!
Hi, thanks for the article.
I think there is a small mistake in the "Number to string/string to number" part...
The example for converting string to number is:
let num = "4"
let stringNumber = Number(s); //doesn't that have to be Number(num);?
Welcome and Noted!!
For me remove duplicates in an array was interesting.....past I removed in another way. It seems like this is so easy....Thank you so much man...It was awesome ππ₯
Welcome Bro!!
I found this article super useful!
Thanks For Reading!!
It varies from person to person like you like it but I personally find it sometimes complicated so I listed it in but thanks for the suggestion!!
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