The Wiert Corner – irregular stream of stuff

What's the most difficult programming concept you can explain in a tweet?

— Tomasz Łakomy (@tlakomy) March 7, 2020

Recursion: https://t.co/0JBbvI5tK0 https://t.co/1jaXmOcuh0

— Shahed Chowdhuri (@shahedC) March 8, 2020

Not being ashamed to admit you don't know something and asking for help

— Predrag Beocanin (@predragbeocanin) March 8, 2020

The most difficult programming concept is simplicity.

It's very easy to write complicated code. It takes practice and effort to write simple code. Do it anyway. Future you and anyone else who works with your code will thank you.

— Nik Kalyani (🎨🔴💜) (@techbubble) March 8, 2020

When a type variable types only read-only locations, it is naturally covariant. When a type variable types only write-only locations,
it is naturally contravariant. When a type variable types both kinds of locations, it is naturally invariant.

— Anders Hejlsberg (@ahejlsberg) March 9, 2020

JavaScript is a language that's viable syntax is dependent on the engine it runs against. Engines exist in browsers and node. All engines must adhere to the ECMAScript standard, but the time of adoption for a particular piece of syntax is not guaranteed.

— Laurie (@laurieontech) March 7, 2020

And passing by value… means you build a copy of your house and give it to me 🤔

— Liam Elliott (@LiamElliott_au) March 9, 2020

A function pointer is a phone number (an address) and you can pass that phone number around or give it to folks. But when you call that number, the person that answers (the function) gives you a list of things to do. That person isn’t the number. The number points to them.

— Scott Hanselman 🌮 (@shanselman) March 9, 2020

calling non existent number does not crash the world (thankfully)

— Jozef Izso (@jozefizso) March 9, 2020

And a C string is a pointer to a *row* of houses, each with a letter on the front door. You read those in sequence until you reach a door that's empty 😆 This analogy is great because I can imagine myself walking down the street…

— Jelmer (@jcormont) March 9, 2020

Programming is creating an effective model in code of the model in your head of the clients model of their need. You will need to use the first to incrementally clarify the other two. Your best tool in this regard is tight feedback loops.

— Garth Gilmour (@GarthGilmour) March 9, 2020

Dynamic Progamming – remembering results that you have already computed so that you don’t have to recompute them in the future.

E.g.

Fibonacci(10) = Fibonacci(9) + Fibonacci(8)

//after this point,you know F(10),F(9) and F(8).

Now F(11) can be computed super fast. = F(10)+F(9)

— Gokul Srinivas (@GokulSrinivas23) March 8, 2020

When going to the toilet, zero length is when there's just toilet roll tube left. Null is there's no toilet roll holder at all.

— Tadhg Lydon (@tadhglydon) March 9, 2020

Async programming is like ordering a pizza while watching TV until it is delivered instead of going and waiting at the door for the delivery guy.

— Nima (@NimaAra) March 8, 2020

map is a function on the array that takes another function. It's essentially forEach and every element in your array is passed into the function and transformed. The result is a new array with all the transformed elements in the equivalent spots.

— Laurie (@laurieontech) March 7, 2020

State machines are pre-defined program flows represented by data, and functions which transform the data.

A state is a unique representation of program data. Every function transforms data from exactly one state to a single new state.

Wizard-style forms use state machines.

— HLS Rev. Chris 'Winter' Stead (@cm_stead) March 8, 2020

Most of the confusion with dates is because you're trying to represent the local time and the UTC time with the same type.

Mark every date as explicitly local or UTC and convert between them.

Comparing two different time zones must always convert to UTC first.

— Isaac Mann (@MannIsaac) March 8, 2020

Essential complexity is what you are trying to solve and accidental complexity is how you try to solve it.
The "what" can't be changed but the "how" is adaptable, don't add complexity just because you like this tool more than that other, use the one that is needed.

— Adrián Norte🇪🇺 (@anortef) March 8, 2020

Async is a keyword that marks a function as returning a Promise.

Any return will be wrapped in a resolved promise and any error thrown will instead return a rejected promise

— Jacob Paris ❖ (@jacobmparis) March 7, 2020

Arrays of Structs: You make 4 dishes. Cut a 1/4 onion, cut 1/4 pepper, mix with 1 egg, add cheese. Fry. Cut 1/4 onion cut 1/4 pepper, mix with 1 egg, add cheese. Fry. Repeat 2x times.

Struct of Arrays: Cut one onion, cut one pepper, mix 4 eggs, add cheese. Split into four. Fry.

— Christoph 🇺🇦 🌻🕊 (@chsiedentop) March 10, 2020

System interrupts: you cook while taking a care of 5 toddlers

— Dom @random82@mstdn.social (@DominikRan) March 10, 2020

A #Closure is a programming technique for storing a function together with its environment, which binds every "free" variable with its value to the function at the time it is created. This allows one to create functions with built-in state and do all kinds of esoteric stuff.

— Anand (@skeptichacker) March 9, 2020

Bytecode is nothing but machine code but targets an imaginary(virtual) machine. JVM is one such imaginary software machine.

— Joe B. Lewis (@vettijoe) March 8, 2020

In Go, the zero value of an interface is nil: it has no concrete type and no concrete value. A non-nil interface value has a concrete type and a concrete value, which may be the zero value of that type, also nil.

— Sameer Ajmani (@Sajma) March 9, 2020