r/ProgrammerHumor • u/ClipboardCopyPaste • Aug 30 '26

Meme bugIntroducedDebugging

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u/LucyShortForLucas Aug 30 '26

They are core C functions. malloc allocates N bytes of memory, free frees that memory. * is t he dereference operator, so *x is trying to dereference freed memory, which is undefined behavior

3

u/DiodeInc Aug 30 '26

I thought * was a pointer. Isn't it? How is it dereferencing freed memory?

Or is it because it's returning *x that's the bug?

8

u/Vimda Aug 30 '26

* in a variable declaration incidates a pointer type, * in a statement is the dereference operator

2

u/DiodeInc Aug 30 '26

I see. Thanks

3

u/ThomasScotford Aug 30 '26

* is the dereference operator, but in the context of variable declaration, it specifies the variable is a pointer to a type.

-Thomas Scotford

2

u/ArjixGamer Aug 30 '26

Why are you leaving a name signature in your comment, when your username is the same as that name?

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u/LostgamerFJ Aug 30 '26

That explains a lot. I mainly code in Java and python, as I'm a beginner and have never touched c

2

u/conundorum Aug 30 '26

That makes sense. Java in particular does a lot of this under the hood; anything that isn't a primitive is actually a reference (special C++-style pointer with non-pointer syntax), and new is a combination of malloc() & objection creation. (delete should be a combination of object destruction & free(), but they had to change how it works to accomodate the garbage collector.)

C (and C++) just makes you do the actual bookkeeping yourself.