how do i convert a string to an integer??

please help.
i need to convert a string (with a numeric value) to an integer. how do i do that in c?
thanks a lot.

Code:

---

int i;
char * string = "1024";
i = atoi(string);
printf("%d", i);

---

But how come when I try to do this

char *string="ARE9";
int key=atoi(string);
printf("%d", key);
cout<<endl;

it only gives me a 0?

Are you trying to create a hash? I don't have much experience with this, but try playing around with bit ops etc..

here's an example (probably not good, just off the top of my head..)

Code:

---

int examplehash(char *string)
{
        int i = 0, hash = 0;

        while(string[i])
        {
                hash += string[i];
                hash ^= string[i];
                ++i;
        };

        return hash;
};

---

Give it a try, play around with it. Do a google search.

*blah, fixed code tag + missing increment :(

Hi wtyyip!

What did you expect :confused: ?

Code:

---

DESCRIPTION
      The atoi() function converts the initial  portion  of  the
      string  pointed  to  by nptr to int.  The behaviour is the
      same as

              strtol(nptr, (char **)NULL, 10);

      except that atoi() does not detect errors.

---

... so you should use strtol.

In fact... you C library is friendly enough to give you 0, it could return you any value it likes (at least with the ISO90 standard).

alex

I guess my question now is: how to I convert character such as ABC back to their ASCII number.
0=48, A=65, B=66 etc...

int x = 'a';

Pretty simple stuff.

printf( "a is %d", 'a' );

Quzah.