Determine the size of an array of strings

Suppose I have a string such as the one defined below. Is there a function that can determine how many items are located in the array?? Like java has A.length, does c++ have something like this?? Thanks

I replied to this post, then deleted it because I thought maybe I spoke too soon. If there's an actual string type of fixed length, I'm unaware of it, but I'm not current on a lot of things.

I don't think the sizeof thing will work unless all items are same size. I may learn something here :-)

I believe this has been covered here before just today.

The number of elements in any array of any type can be calculated like this:


for example, an array of strings


Note that the above for strings does NOT calculate the number of characters that the strings point to. It only tells you how many different strings are in the array.

That only works if each string in the array is the same length. For instance, if A = {"aaaaaaaaaaaaaaaaaaaaaaaa","foo","bar","baz","a","a"}, then your method would not work as intended, afaik.

You just flunked C++ 101 course. sizeof(string) does not include the characters. Try this simple example

I know you think you answered this, Dragon, but you didn't. I'm asking for the definition of type string or the name of a header file or other document where it can be found, so I can learn.

Picking at a non-existent pimple in the pursuit of guruness is counterproductive and helps no one. If your solution works, then the type definition has to produce a fixed-length item, whether it's an integer or fixed-length string, or whatever.

I am sorry if I misunderstood your original question. string is a c++ STL (Standard Template Library) class, and can be found in <string> header file -- note that current version does not have an extension, but some very old c++ compilers may require the .h extension.

I wouldn't spend too much time studing the source code because from what I saw it is almost unreadable. Better to use a tutorial, or read the book about its functions.

I'm sorry. I never had the need to do sizeof(string), only size of the array itself and other pointers. I did not realize that it would work that way.

Also please note that the correct use of the sizeof operator is not a trival matter. It is use in many many situations. If one does not know how to use it correctly, it will produce unexpected, and probably unwanted results.

One just has to remember that the string class is a fixed-length object regardless of how may characters it points to. This is not the same an a char array, which may include all the characters.


the sizeof operator used on each of the two above arrays will produce significantly different results. The sizeof(array) includes all the characters in "Hello World", while the sizeof(str) does not.

Excellent. Thank you for pointing that out to me. I think you just made my coding life a /lot/ easier.

You're welcome. They don't call me "Ancient" for nothing!

Thanks. That's pretty gross, alright, and I used to think the Win API macros were bad...

I don't want to beat this to death, but catz's problem is solved and maybe it'll be interesting. It is to a guy that's been out of the trenches for 10 years.

string is a typedef of basic_string, which is associated with a number of things, including a traits structure. You don't wanna know about the 'E's, 'T's, and 'A's unless you're trying to develop a headache.

The item stored in each element of string A[] isn't the string and it isn't just a simple pointer, but the effect is the same: they're all the same size, 16 bytes, as revealed by the sizeof operator. The actual size of the individual character entities may be retrieved by A[0].size() and so forth. (You can resize them without actually changing their textual value; they get padded with nulls or whatever's specified.)

Regards, old Bubba David, got 3 years on Ancient :-)