how to find the length of an array in c/c++ ?
Author
hi all
I was wondering if there is a way to find out the length of an array in c or c++
for example:
char *animals[] = {"cat", "dog", "mouse", "elephant, "rhino", "snake", "fish"};
is there a function that would return to me the number of animals that are stored in this array?
In flash for example it would be something like:
int num_of_animals = animals.length();
========================================================
ALso is there a way i can find all the functions that my complier has? for example:
printf()
scanf()
etc,,, will it be in a help file?! i am using bloodched Dev-C++
thx
Li
For a statically allocated array you can use number_of_elements = sizeof(array)/sizeof(type_of_array); In your example: number_of_animals = sizeof(animals)/sizeof(char *).
For dynamic arrays, you either need to store the number yourself or use a class like std::vector.
For dynamic arrays, you either need to store the number yourself or use a class like std::vector.
You can, however, use the SC++L containers, such as std::vector and std::list. [smile]
It's very unlikely the compiler comes with such a list (I've never used bloodshed, so I'm not totally certain, but fairly confident).
There is, however, a plethora of online sources, such as MSDN.
Quote:
ALso is there a way i can find all the functions that my complier has? for example:
printf()
scanf()
etc,,, will it be in a help file?! i am using bloodched Dev-C++
It's very unlikely the compiler comes with such a list (I've never used bloodshed, so I'm not totally certain, but fairly confident).
There is, however, a plethora of online sources, such as MSDN.
Here is a little sample of how you could use the vector like SiCrane mentioned.
You can also treat the vector<> like an array with Animals, but I feel like you loose some of the functionality built into vector working like that.
#include<vector>#include<string>int main(){ std::vector< std::string > Animals; Animals.push_back("cat"); Animals.push_back("dog"); Animals.push_back("mouse"); Animals.push_back("elephant"); Animals.push_back("rhino"); Animals.push_back("snake"); Animals.push_back("fish"); int sz = Animals.size(); std::cout << sz << std::endl; std::vector< std::string >::iterator b = Animals.begin(); std::vector< std::string >::iterator e = Animals.end(); while(b != e) { std::string name = *b; std::cout << name << std::endl; ++b; } system("pause"); return 0;}You can also treat the vector<> like an array with Animals, but I feel like you loose some of the functionality built into vector working like that.
if you assign the iterators like that does it change with the vector; If I put iter = .end() would it still point to the end when I add items.
Quote:Original post by Zaris
if you assign the iterators like that does it change with the vector; If I put iter = .end() would it still point to the end when I add items.
I think .end() will ALWAYS point to the last element, no matter how you added it.
Quote:Original post by perfectly_darkQuote:Original post by Zaris
if you assign the iterators like that does it change with the vector; If I put iter = .end() would it still point to the end when I add items.
I think .end() will ALWAYS point to the last element, no matter how you added it.
It usually points to 1 past the last element. Otherwise when you loop until end() you will stop before actually using the last element.
Quote:Original post by Zaris
if you assign the iterators like that does it change with the vector; If I put iter = .end() would it still point to the end when I add items.
No, it won't.
This topic is closed to new replies.
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