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Killer JavaScript One Liners

Shshank on July 22, 2022

Some useful JavaScript One-Liners After a good response from the community, I decided to post some few more JavaScript one liners, that might help...
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frankwisniewski profile image
Frank Wisniewski •

seen 1000 times and wrong 1000 times...

const str = 'Hello 😊 World';
const reversedStr = str.split('').reverse().join('');
console.log(reversedStr); // 'dlroW �� olleH'
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ecyrbe profile image
ecyrbe •

You should then post the right one :

const str = 'Hello 😊 World';
const reversedStr = [...str].reverse().join('');
console.log(reversedStr); // 'dlroW 😊 olleH'
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frankwisniewski profile image
Frank Wisniewski •

You too ....

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ecyrbe profile image
ecyrbe •

You made a critique without even trying to help. That was my point.
If you have knowledge, you should share it.

Thanks Luke for taking the time to add a fool proof version.

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frankwisniewski profile image
Frank Wisniewski •

this has been chewed through here so many times, a simple search is enough... dev.to/ianfelix/how-to-invert-a-st...

 
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Adam Crockett 🌀 •

You could also hard code the string backwards 😉

const string = "olleh"
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That's the efficiency of build time.

Nice one Luke

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Jan Küster •

Luke you should make this comment a new article do we can bookmark it 🙃

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adam_cyclones profile image
Adam Crockett 🌀 •

Oh man an article on hard coding strings where could that lead 🤪

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bias profile image
Tobias Nickel •

at least it does not lead to a configuration or environment variable called empty_string.

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adam_cyclones profile image
Adam Crockett 🌀 •

I don't know what that is 👍

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joolsmcfly profile image
Julien Dephix • • Edited

Clear all cookies is more of a tiny program than a one-liner ;)

To capitalise a string you could use the same technique as to reverse a string.

const upper = s.split("").map(n => n.toUpperCase()).join('');
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I find it easier to read / understand than two replace.
Hope this helps.

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frankwisniewski profile image
Frank Wisniewski • • Edited

you have to understand the task...

s='this is a mistake';
const upper = s.split("").map(n => n.toUpperCase()).join('');
console.log(upper === s.toUpperCase()) // true
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joolsmcfly profile image
Julien Dephix •

Ha, my bad! I read too quickly.

I guess I should not be reading code on my phone at 11pm. 😓

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Jon Randy 🎖️ • • Edited

Your random hex function has a number of problems. For starters, it will never return #ffffff. Also there are many other values it will never return as you're using padEnd instead of padStart

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Jon Randy 🎖️ • • Edited 
const hexClr = ()=>'#'+(~~(Math.random()*8**8)).toString(16).padStart(6,0)
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feba33 profile image
feba •

I personally use this to capitalize:
str[0].toUpperCase() + str.substr(1)

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prajyu profile image
prajyu •

How about adding another one liner
To remove duplicate values

const uniqueValues= (arr) => [...new Set(arr)];
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