Image Transcription: Meme
[Four images of toilet roll holders, each with text above them.
The first shows a toilet roll holder holding a partially-used roll of toilet paper. Its text reads, “Non-zero value”.
The second shows a holder holding a completely used roll of toilet paper, leaving just the cardboard tube. Its text reads, “0”.
The third shows a holder with no toilet roll or cardboard tube on it at all. Its text reads, “null”.
The fourth shows no holder; simply plain wall. Its text reads, “undefined”.]
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Good human.
not sure the distinction between null and undefined is doing anything for me here
Basically JavaScript uses undefined to mean keys that don’t exist. You know how sometimes when you’re wondering about the semantics of “present but null” and “absent”? It’s basically that. Undefined means it isn’t there but things are only null if they’ve been set to null.
There are probably more nuances but that is the gist.
I knew someone that had the null set tattooed on felt they had made a deeply philosophical statement by doing so.
Now give me a negative number
Roll held in under-hanging fashion, with free end against the wall.
I see how you censored at “undefined”. Thanks. The actual value could easily kill anyone who sees it.
Now make one with someone pointing at it for NULL pointer vs tp pointer.
In C/C++, undefined should be the meme of the little girl smiling while the house burns down behind her.
In C. In C++, the image is zalgoified, corrupted, cropped, lens flared, color-inverted, and for some reason converted to Targa file format.
No, at least for JS the picture for undefined should actually be for “not defined” which yes is different. Undefined would be an empty holder without the spool holder.
0 = a 0 value
null = a value that means no value
undefined = the variable doesn’t point to a value
not defined = there is no variable or anything
Rust is neat because it doesn’t have the bottom 2
Lack of support for nulls sounds like a huge pain in the ass.
It also doesn’t have throw/try/catch. If a function can fail, it returns a Result and you have to deal with the failure case explicitly.
It has std:option
So every object that can be None or Some, needs to be checked when used. And only options can be set to None
*Laughs in Option<T>*
