Re: [Dev-C++] <Dec-C++>Please give me your feedbacks!

i'd look into this handy little function from string.h if I were you: 

size_t strlen(const char* cs)
returns the length of string cs without counting the terminator

and, stdlib.h has a atoi (array to int)  function already, so this is
kinda reinventing the wheel, as most arch's that have a c compiler
also have a complementary c library.

also, converting a string to a regular int seems like it would only
have limited use as you can only assume that an int is 16 bits, making
the range of possible values this function can return  32767 to -32768
or 0 65535 if it is an unsigned int.  if you need to process arbitrary
length numbers, there are some good, albeit non-standard libraries
available for both c and c++


good luck though.
Cary

On Fri, 5 Nov 2004 11:17:54 +0100 (CET), Per Westermark
<pw...@ia...> wrote:
> 1) If you have problems with school assignments, why don't you just admit
> that?  An embedded system - where there might not be an existing RTL,
> forcing the developer to write it's own strtoi doesn't need wide character
> support...
> 
> 2) Why do a loop that both uses an index and counts size? Why isn't the
> size variable enough to locate the last character. Why isn't this loop
> breaking at the first non-digit?
> 
> 3) Real strtoi doesn't write any error messages. There might not even be a
> console for emitting any messages... It should just stop at the
> first invalid character.
> 
> 4) Why do nested loops for exponent? A real implementation converts from
> end of string, just multiplying the previous sum by 10 every time it has
> one more digit to process.
> 
> 5) You have missed handling numbers starting with a sign. 6) How do you
> think you can load a text string with scanf without allocating the memory.
> You have a pointer but that doesn't point to a text buffer for storing
> your digit string.
> 
> /Per W
> 
> 
> 
> On Fri, 5 Nov 2004, Justin Fan wrote:
> 
> > Hi,
> >
> > I'm newer to C++ programming so I hope you can help me to improve my
> > coding skill. Here is my first code to implement Strtoi(char*), please
> > give me your feedback.
> > My lead ask me to implement it as Strtoi(wchar*), but I can't find
> > which head contains the definition of wchar and how to use it. And
> > some known bugs are there after tesing:
> >
> > when I input a long string such as "12345678987654321", this app will crash.
> > Also when I add a sentence before sleep(), it crashed.
> >
> > BTW, I want to know how to debug an app and how to track views I added.
> >
> > Any ideas?
> >
> > Thanks in advance and any suggestions will be appreciated!!
> >
> > #include <stdlib.h>
> >
> > int strtoi(char* a)
> > {
> >
> >       int sum=0,size=0,i=0;
> >
> >       while(a[i]!='\0')               // calculate the size of the array
> >       {i++;size++;}
> >
> >       printf("The size of string is: %d\n",size);
> >       i=0;
> >
> >
> >       for(i=0;i<size;i++)
> >       {
> >      if (a[i]<'0' || a[i]>'9')                //Don't deal with invalid strings
> >        {      printf( "I think it's meaningless to covert a English word to
> > int.\n        Please input some string such as 123");
> >               return 0;
> >        }
> >       else
> >          {
> >           int j=0;                    //variable 'j' refers to the exponet of 10
> >         int temp=a[i]-'0';              //covert a[i] to a interger
> >           for(j=size-i-1;j>0;j--)       //sum
> >              temp=temp*10;
> >
> >         sum+=temp;
> >         }
> >     }
> >      printf("The result of convertion:%d\n",sum);
> >      return sum;
> >
> > }
> > int main()
> > {
> >   int i=0;
> >   char* a;
> >   printf("Please input your string,such as 123\n");
> >   scanf("%s",a);
> >   strtoi(a);
> >   sleep(100000);
> >   return 0;
> > }
> >
> > --
> > Thanks
> > Z.J.
> >
> >
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