Small Javascript things I did not know until today

DanielJune 22, 2021June 23, 2021

I always get a dopamine hit when I discover a short, bite-sized post that teaches me a new CSS or JS trick. Maybe the zapping culture is to blame for this 😀

Therefore you can imagine the joy I've had when I've discovered til.hashrocket.com. Spend a few hours jumping from one tip to another. Twitter style!

Below are some JS things I did not know about and learned from it:

1. In an arrow function, we don't have access to the arguments object link.

() => {console.log(arguments)}
// will opuput arguments is not defined

However, it seems there is a workaround for this.

2. We have a property to get the name of a function in Javascript link.

const a = function myName() {};
console.log(a.name);
// will oputut myName

3. There is a .stack property on the Javascript errors that allows us to log the stack trace link.

A bit like using the console trace

function firstFunction() { secondFunction(); } 
function secondFunction() { thridFunction(); } 
function thridFunction() { console.log(new Error().stack); } 

firstFunction();

//=> Error 
//  at thridFunction (<anonymous>:2:17) 
//  at secondFunction (<anonymous>:5:5) 
//  at firstFunction (<anonymous>:8:5) 
//  at <anonymous>:10:1

4. There is a paste event, that allows us to manipulate the pasted data in an element link.

For example in a textarea.

const textarea = document.querySelector('#my-textarea');
textarea.addEventListener('paste', (event) => {
    // manipulate date in event
});

There are maybe even more Javascript tricks, so if you have time go check them out on til.hashrocket.com.