Inputting strings into char arrays without knowing array size
I really have two questions. The first one I think I already know the answer to, but confirmation would be nice: Is it a bad idea to read data into an array if you do not know the size of the array?
Secondly, is there a way to input a string and store it in a char array without knowing the size of the array? All of the functions I have seen require the size of the array to be passed in. However, the lab question I am working on simply states: "Read a string into character array variable state." I need to write the code to accomplish that. There is no definition of the "state" array, nor of its size. I wrote a line where I assumed the size of the array, but I am curious to know if there is a way to accomplish the same thing without specifying the size of the array.
Secondly, is there a way to input a string and store it in a char array without knowing the size of the array? All of the functions I have seen require the size of the array to be passed in. However, the lab question I am working on simply states: "Read a string into character array variable state." I need to write the code to accomplish that. There is no definition of the "state" array, nor of its size. I wrote a line where I assumed the size of the array, but I am curious to know if there is a way to accomplish the same thing without specifying the size of the array.
| Is it a bad idea to read data into an array if you do not know the size of the array? |
It depends on the situation. Sometimes you can assume the array will be large enough to hold the string.
But usually -- yes -- it's a very bad idea.
| Secondly, is there a way to input a string and store it in a char array without knowing the size of the array? |
Why can't you know the size of the array?
It almost sounds to me like you need to just pick a size for this array and use that. Try to pick one that will be large enough to hold any (reasonable) input.
@Disch: Thanks for the response. That is essentially what I did in my answer to that particular question. I assumed a maximum of 100 characters in the array and wrote the code for that input. I just wanted to make sure I wasn't missing another way to do it.
another way to go about this problem is vectors!
look up the push_back method for the vector class, something along the lines of,
vector_name.push_back (item_to_put_in_vector);
hope this helps!
look up the push_back method for the vector class, something along the lines of,
vector_name.push_back (item_to_put_in_vector);
hope this helps!
Well since he's working with string data the logical choice would have been a std::string. But I assume this was an assignment that specifically required char arrays.
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