Re: Logic AND between some strings
On 2011-03-07 16:53:50 -0500, crea said:
Paavo Helde wrote:
"crea" <no@invalid.com> wrote in
news:Iz9dp.103060$9b3.52587@newsfe23.ams2:
Paavo Helde wrote:
"crea" <no@invalid.com> wrote in
news:qO7dp.24381$2H.20090@newsfe15.ams2:
yagru_alvarez wrote:
I have some strings, all of them such as the following type:
0111001
I want to make a LOGIC AND between all of them. How can I perform
that in C++. Thanks.
Here you go:
string StrAND(char* s1, char* s2)
'string' is not defined, probably you mean std::string.
yes
One should use const char* instead of char*.
Why the strange interface, why not use const std::string& instead of
const char*?
Looked to be faster/ easier to code.
{
char buffer[100];
string ret;
not needed
int a, b, c;
no need to predeclare variables in C++.
?. variables needs to be declared.
But not in the beginning of the function.
a = atoi( s1 );
How do you know the result fits in int? atoi() provides no error
check.
Well he said it was fixed size strings, so I assumed that they are
not very long. In his exaple they were like 100110. Obviously this
function is for short values. If he knows all are short, then he
could use this. Its faster to code than going bit by bit. Time is
money .. :).
Without error checking this function will silently give wrong results
some day. Always check for errors!
And last, this function still does not do what he wants. When applied
to "0111001" and "11000", it yields "8344". I am quite sure this is
not the expected result.
oh, it needs a for-loop to go every bit individually... but similar
logic anyway
No, it just needs to a text string that represents the integer value in
binary. Read about strtoul. You're right that looping through the
individual characters is a better approach; but that's not "similar
logic" at all.
--
Pete
Roundhouse Consulting, Ltd. (www.versatilecoding.com) Author of "The
Standard C++ Library Extensions: a Tutorial and Reference
(www.petebecker.com/tr1book)
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