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Nick Taylor
Nick Taylor

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February 17th, 2022: What did you learn this week?

It's that time of the week again. So wonderful devs, what did you learn this week? It could be programming tips, career advice etc.

![Yoda wooping someone's butt](https://media.giphy.com/media/yDYAHbqe5DfyM/giphy.gif)

Feel free to comment with what you learnt and/or reference your TIL post to give it some more exposure.

#todayilearned

Summarize a concept that is new to you.

And remember, if something you learnt was a big win for you, then you know where to drop it as well.👇👇🏻👇🏼👇🏽👇🏾👇🏿

![Little kid making a fist as if to say "Yes!"](https://media.giphy.com/media/6brH8dM3zeMyA/giphy.gif)

Top comments (21)

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aruna profile image
aruna-x

I learned that git switch is useful for moving changes over to a new branch if you forget to checkout before working 🙃 Stuff happens 🤷‍♀️

In the process of getting feedback about my recently engineered portfolio site, I also learned to better value my talents as a dev, instead of being so modest I “undersell” myself. I have no interest in overselling either - but self confidence is somewhere in the middle, and I’m learning to be there more often. Getting ample feedback about my projects from my dev friends helps that along :)

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nickytonline profile image
Nick Taylor

Awesome!

Hackerman from Kung Fury putting on a Nintendo Power glove

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kayis profile image
K • Edited

I'm currently creating a Web3 course and so I read about elliptic curve cryptography. I wanted to understand what the keys in Ethereum actually are.

ECC is based on elliptic curves; basically, math functions on a 2D space (x/y).

ECC on Ethereum uses a particular standard curve, called secp256k1.

This curve is defined by the equation y²=x³+7 mod p or y=sqrt(x³+7) mod p

The curve doesn't use the real numbers, but a fixed set of numbers called a finite field.

A fixed set of numbers, in this case, means there are 115792089237316195423570985008687907853269984665640564039457584007908834671663 numbers in the field that secp256k1 is defined for. This number is the p from the equation above, a large prime number. Crazy big, but still smaller than all real numbers, lol.

The idea here is if you calculate something and it gets greater than p, you get an overflow and go on from 0.

The private key is just a random integer between 0 and p.

This integer defines how often a base point g on that curve has to be added to itself to get the public key. The base point g is also predefined by secp256k1, and since it's a point on that curve, it's an x and y coordinate on the curve, and basically two big integers.

So, if the private key was 5, the public key would be the result of g+g+g+g+g.

The + isn't a common addition but a more complex operation that uses two points (in this case, both g) to calculate a new point on the curve.

So, the public key would be a point, or an x and y coordinate on that y²=x³+7 mod p curve. Both x and y will be integers smaller than p because of overflow etc.

So to sum all up.

The private key is a random 256bit integer smaller than that big prime I mentioned.

The public key is two integers, essentially x and y coordinates, defining a point on the secp256k1 curve. You get this point by executing a special kind of addition on a predefined base point "private key times".

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nickytonline profile image
Nick Taylor

That's awesome! 🔥

Yes, that's awesome!

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mrsharm profile image
Mukund Raghav Sharma (Moko)
  • Started a course my Mitch Horowitz.
  • Got a job offer to work with one of my Heroes in the Garbage Collection space. Going nuts about it but have set myself on a journey to master everything about the CLR.
  • More Virtual Memory work via this
  • Learnt that you can embed a style inside any tag such as: <p> <style "background-color:red"> hi </style></p>`.
  • Read more from Company of One been so behind on my reading because I have been incredibly busy with interview stuff.
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nickytonline profile image
Nick Taylor

Nice!

A kangaroo playing an electric guitar

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dbc2201 profile image
dbc2201

I started learning JavaFX again, left it some years ago because my job didn't allow much time for it. The new thing I learned about it is there isn't enough documentation or resources to properly get started, it feels staggered. Compared to the UI libraries of C#, Microsoft did a very good job to make it feel more cohesive with the .net platform for developers, wish Oracle could do the same.

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nickytonline profile image
Nick Taylor

Borat saying Great Success!

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snikhill profile image
Nikkhiel Seath

I learnt that I need to conserve my keystrokes and use writing as a medium to convey my point to a larger audience.
Based on this advice, I wrote documents for a service that I am implementing at work.

Along with this, I am adding a blog functionality to my website (using DatoCMS) and shall be sharing/learning in public using my writing. (I shall keep you updated on this).

I am continuing my financial education using books and have finally sought a financial adviser to better guide me through my journey.

May I please know what you learnt @nickytonline ?

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nickytonline profile image
Nick Taylor • Edited

Jean-Luc Picard from Star Trek TNG saying Well done!

What I learnt this past week was that there are now Netlify scheduled functions.

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meatboy profile image
Meat Boy

Recipe for carrot muffins. Seriously, my biggest discovery of the week :D

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nickytonline profile image
Nick Taylor

Nice!

Nice

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nkemdev profile image
Nkem

I am currently learning Javascript with Scrimba. Learning by building apps.

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nickytonline profile image
Nick Taylor

Pam from The Office saying Nice!

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cerchie profile image
Lucia Cerchie

I learned how to get started with a MongoDB database

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nickytonline profile image
Nick Taylor

Let's go!

A kid twirling in a cowboy outfit firing pistols that are their fingers

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waylonwalker profile image
Waylon Walker

visidata is such a good tui for almost all things json, including aws eventbridge rules comfing from the cli.

waylonwalker.com/til/aws-eventbrid...

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nickytonline profile image
Nick Taylor

BB-8 giving a thumbs up

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deathvenom54 profile image
Deathvenom

Completed my project github.com/DeathVenom54/github-dep...
Proud of it, and explaining article coming soon :D

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nickytonline profile image
Nick Taylor

Noice!

Noice!

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ryannerd profile image
Ryan Jentzsch

This is embarrassing but I'll share anyway. I've been developing software for over 25 years. I spent 3 hours today trying to figure out why in my react app that I assigning the variable document to a File object and document kept showing as undefined. Well, friends document is a reserved word in JS (at least that's how Babel seems to be treating it under the hood). But instead of throwing errors that I did something stupid it failed silently and just assigned undefined. Very frustrating.