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Marko Denic
Marko Denic

Posted on • Updated on • Originally published at markodenic.com

JavaScript Secrets

In this post I will share with you JavaScript tips you won’t find in most tutorials. Enjoy!

What is JavaScript?

JavaScript is a scripting language that enables you to create dynamically updating content, control multimedia, animate images, and so much more.

Let's jump to the tips!

* Shorten an array

You can set the length property to shorten an array.

Shorten an array

* Short-circuits conditionals

If you have to execute a function only if condition is true, you can use short-circuit.

Short circuit conditionals

* Show specific console.table() columns

By default, console.table() lists all elements in each row. You can use the optional “columns” parameter to select a subset of columns to display:

Show specific console.table() columns

* Remove duplicate elements from the array:

Remove duplicate elements from the array

* Convert a string to number:

Convert a string to number

* Convert a number to string:

Convert a number to string

You can find more HTML/CSS/JS Tips here: github.com/MarkoDenic/awesome-html-css-js-tips

If you liked this article, be sure to ❤️ it.

This article is a repost from my blog. Find the original post here: JavaScript Tips.

Let's keep in touch:
Blog: markodenic.com
Twitter: @denicmarko
Github: github.com/MarkoDenic
Codepen: codepen.io/denic

Discussion (10)

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dsbarnes profile image
dsbarnes

Excellent tips. I remember learning how to short circuit through counting substrings of a string like so:

arr.forEach(e => obj[e] = (ojb[e] || 0) + 1));

Changed my life.

Never knew about console.table(), that is just awesome.
Appreciate you sharing

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denicmarko profile image
Marko Denic Author

Hey @dsbarnes , thanks for reading and taking the time to comment. Glad you like it.

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stojakovic99 profile image
Nikola Stojaković • Edited on

Converting a string to a number with a plus sign is a hack and is therefore one of the things you shouldn't do in JavaScript (just like changing the length property of an array).

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denicmarko profile image
Marko Denic Author

Hi Nikola, thanks for reading. Yes, these two are tricks definitely. But, I saw both on MDN docs and w3docs, so I would consider them a legit tricks. :)

How do you like the rest?

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olgagnatenko profile image
Olga Gnatenko

What about explicit conversion from string to number: str => Number(str)? I think this one is clearer and easier to understand/note for other developers.

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abourass profile image
Antonio B.

parseInt(str, 10)

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denicmarko profile image
Marko Denic Author • Edited on

Hi Olga. Hi Antonio.
Thanks for reading and taking the time to comment.

There is at least 10 different ways to convert a string to number. Maybe I create a dedicated post about this topic.

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myzel394 profile image
Myzel394

Awesome! Has someone benchmarks for +str and parseInt(str)?

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sergix profile image
Peyton McGinnis

I actually didn't know some of these. Some great tips!!

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denicmarko profile image
Marko Denic Author

Thanks Peyton. Glad you like it. :)