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using strcpy in c++ error

Posted on 2011-03-21
Last Modified: 2012-08-13
Can you please tell me what's wrong with this code?
I need to use strcpy for my homework and I keep getting a "Run-time check failure #2:Stack around st2 was corrupted"

btw, I am trying to just print State

Thanks guys!

using namespace std;

int main(){
	char st1[20]="State of Ca";
	char st2[5]={' '};

	strcpy(st2, st1);
return 0;

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Question by:pgmerLA
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Accepted Solution

crysallus earned 300 total points
ID: 35185946
st2 is only 5 elements in size, which is too small to fit all of st1 in it. If you only want to copy part of the string, then use strncpy, where the third argument is the no. of char's to copy. Eg:

const int ST2_LEN = 5;
char st2[ST2_Len] = {' '};
strncpy(st2, st1, ST2_LEN);

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Author Comment

ID: 35185954
is there any way I could use strcpy?

Expert Comment

ID: 35185967
strcpy always copies the whole of the source (st1), into the destination (st2), as such the destination must be at least as large as the source, including null-terminating character.

So, to copy only "State", or have the destination string smaller than the source, no.
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Assisted Solution

phoffric earned 200 total points
ID: 35186107
BTW, if you want to store "state" as a c-style string in an array, then don't forget that you need a terminating null byte for a total of 6 bytes. Your st2 is only 5 bytes.
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Expert Comment

ID: 35186111
oops, crysallus, I didn't see that you said "including null-terminating character". So, never mind.

Expert Comment

ID: 35186181
Actually, you were still kind of right to pick up on that, as I hadn't put 6 in my sample code in my first post, which I should have.

But yes, my explanation there probably should have got that across.

Author Comment

ID: 35186453
Thanks guys.

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