I am new to CS50 and teaching AP Comp Sci Principles for the first time this school year. One of my students asked it there was a limit to the amount of bits get_string() can store. I wasn't sure what to tell him...

I know there are limitations to int and float (32 bits) unless you use unsigned, double, and long long but I was stumped on the string question. Thanks!

2 Answers 2


That one's probably limited only by the memory it can allocate in a contiguous chunk. On the cs50.io machines, with 512MB of RAM plus swap, that might be a hundred million characters, something around that. But interesting thought, haven't tried.

PS: You can find the source of get_string in https://github.com/cs50/libcs50/blob/master/src/cs50.c (basically: uses realloc a lot, increasing buffer size by factor 2 and shrinking down later)


we can think that get_string () is equivalent to char *, we can use dynamic memory storage

char* name = malloc(memory we need)

although the get_string () function handles memory somewhat differently, it is essentially the same. In short there is no explicit limit for memory storage more than the limitations of our system

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