This content originally appeared on DEV Community and was authored by Pratap Sharma
In this article, let us cover some tips and tricks of Javascript everyone should be aware of.
Convert to boolean
All values in javascript are truthy except for 0, "", null,undefined, NaN and of course false.
We can easily switch between true and false by using the negative operator(!), which also converts the type to boolean.
console.log(!0); //true
console.log(!1); //false
console.log(!!0); //false
console.log(!undefined); //true
Amazing right?
Convert to Number
Converting to number can be easily achieved using the addition operator (+).
let num = "10";
console.log(num); // "10"
console.log(typeof num); // "string"
num = +num;
console.log(num); // 10
console.log(typeof num); // "number"
How cool is that?
Quick float to integer
There are several ways to convert float to an integer by using Math.floor(), Math.ceil() or Math.round(), but there is also a quicker way to convert a float to an integer by using the bitwise OR operator (|).
console.log(11.5 | 0); // 11
console.log(-11.5 | 0); // -11
Wow! Amazing right? I started using this more frequently now.
Short-Circuit Evaluation
Using &&
Using && will return the first false or falsy value. If every operand is expected to be true, then the last evaluated expression will be returned.
console.log(true && true && 2); // 2
console.log(true && false && 2); // false
Using ||
Using || will return the first true of truthy value. If every operand is expected to be false, then the last evaluated expression will be returned.
console.log(true || false || 2); // true
console.log(false || false || 2); // 2
Short-Circuit evaluation is widely used in any programming language.
Filter unique values from an array
You can easily find unique values using the Set data structure. The Set was introduced in ES6 along with the spread operator (...). Let us use both the new concept to filter unique values of an array.
I know you'll use this a lot. You can thank me later. ?
let arr = [1, 1, 2, 3, 4, 4, 5, 2, 3, 6];
const uniqueArr = [...new Set(arr)];
console.log(uniqueArr); // [ 1, 2, 3, 4, 5, 6 ]
Self calling function or IIFE
IIFE - Immediately Invoked Function Expression
This is often called as Self-Invoked Annonymous Function or IIFE. It is a function that executes automatically when it gets created.
(function () {
console.log("I am running automatically");
})();
//I am running automatically
You can read more about IIFE here.
Get a random item from an array
We can use Math.random() and Math.floor() methods to get a random item from an array.
let names = ["Pratap", "Prasar", "Sudip", "Shiva"];
let randomName = names[Math.floor(Math.random() * names.length)];
It is also one of the most commonly used tricks.
Primitive operations can be faster than function calls
Keep in mind that primitive operations can be faster than function calls.
Instead of using
const min = Math.min(a, b);
use
const min = a < b ? a : b;
Empty an array
You can empty an array using the array.length property.
let dumarray = [1, 1, 2, 3, 4, 5, 6, 7];
dumarray.length = 0;
console.log(dumarray); // []
To sum it up
This is it from this article. I hope I'm able to help you with top Javascript tips and tricks.
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Please don't hesitate to drop a comment here if I miss anything. Also, let me know if I can make the post better.
This content originally appeared on DEV Community and was authored by Pratap Sharma
Pratap Sharma | Sciencx (2021-06-09T03:31:05+00:00) Tips and Tricks in Javascript. Retrieved from https://www.scien.cx/2021/06/09/tips-and-tricks-in-javascript/
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