garbage in loop for no reason

Question

i wrote a function that receives a string as a char array and converts it to an int:

int makeNumFromString(char Str[]) 
{
    int num = 0, len = 0;
    int p;
    len = strlen(Str);
    for (p = 0; p<len; p++)
    {
        num = num * 10 + (Str[p] - 48);
    }
    return num;
}

the problem is that no matter how long the string i input is, when "p" gets to 10 the value of "num" turns to garbage!!! i tried debbuging and checking the function outside of the larger code but no success.

what could be the problem and how can i fix it? THANKS

Answer 1

Perhaps your int can only store 32 bits, so the number cannot be higher than 2,147,483,647.

Try using a type for num with more storage, like long.