`malloc` won't fail, right?

the javascript will enforce the user input. no need to have the backend check it again!

This should be a joke, but considering how often it's actually the case it's unfortunately not that funny.

Not as much as developers who can't find their own coding errors might have you think!

It won't on Linux! But hey, random processes will get OOM-killed.

You can turn off overcommit, in which case you'll get a null return instead of OOM killing.

But also, you can still get a malloc failure without actually be running out of memory if the allocator can't find a big enough contiguous chunk of address space.

This is highly unlikely on a 64 bit system, but if you try to malloc gigabytes on a 32 bit machine you might see it.

And also, you never know when this theoretical case actually happens but it did happen to me: at one point someone may use your code on an Arduino and unexpectedly, it works! But memory allocation could fail more than you expect!

On Unix it won't. You can overcommit memory and only get into trouble when you actually try to page it. But not at malloc time.

Iirc that's configurable.