Question involving converting array->int

[Unregistered]

I have an array (char iiword[256];).
I filled it with iistream.get()s.
When i use printf("%s", iiword); the actual number I want is displayed.
However, i do not know how I can convert the printed number into an integer.
Anyone have any idea how to do this? Thanks.
-Drekenzin

[Crossbow]

Just write a simple function that accepts the character and converts it to it's respective integer. Basically something like:

int convert(char number)
{
  if(number < '0' || number > '9'){
      return -1; //check for -1 when using function 
   }
   switch(number)
   {
    case '0':
         return 0;
    case '1':
         return 1;
     //etc.....
   }
}

Just loop through the array and check to be sure the chars are really 0-9 with a similar if statement like above, then send that element of the array to the function. Reply if this doesn't work and I will try to fix it(I did that out of my head).

[Unregistered]

The thing is, the array holds the individual digits of the integer.
for example:
iiword[0] = 1
iiword[1] = 5
iiword[2] = 9
...
i'd want to get 159 set to an integer.
do you know how to do this?

[Crossbow]

Oh, well in that case you could do something like this:

int convert(char *string)
{
int tempnumber = 0;
int number = 0;
int place;
   for(unsigned int i=0; i<strlen(string); i++)
   {
       switch(string[i])
       {
        case '0':
             tempnumber = 0;
             break; 
       case '1':
             tempnumber = 1;
             break;
       //etc...
       }
       //now find out what place value the number holds
       if(!strlen(string)-i)
          place = 1; 
       else{
          place = strlen(string)-i;
       number += (place * tempnumber);
      }
   }
return number;
}

Something like that. You will have to complete the switch statement of course, and I am not sure if the place thing will work or not. Tell me if it does or doesn't.

[Unregistered]

nope, that doesn't work =(

[Crossbow]

Appearantly math isn't my strong point. Since our number system is base 10 I need to make the number 10 to the power of place * tempnumber. Stupid me! :-) Here is the revised code:

int convert(char *string)
{
int tempnumber = 0;
int number = 0;
int place;
   for(unsigned int i=0; i<strlen(string); i++)
   {
       switch(string[i])
       {
       case '0':
             tempnumber = 0;
             break; 
       case '1':
             tempnumber = 1;
             break;
       case '2':
             tempnumber = 2;
             break; 
       case '3':
             tempnumber = 3;
             break;
       case '4':
             tempnumber = 4;
             break; 
       case '5':
             tempnumber = 5;
             break;
       case '6':
             tempnumber = 6;
             break; 
       case '7':
             tempnumber = 7;
             break;
       case '8':
             tempnumber = 8;
             break; 
       case '9':
             tempnumber = 9;
             break;
       }
       //now find out what place value the number holds
       place = strlen(string)-i;
       number += (pow(10,place) * tempnumber);
       cout << i << "\n";
   }
cout << "\n";
return number/10;
} 

Be sure to include math.h for the pow function.

[Unregistered]

hi, you can go to the topic named "something wrong with this?". I posted a function where my code might be useful to you. this algorithm can be used without using strlen(); what it does is something like this:

//replacement code (used inside the code to replace the strlen() )

long int storage=0; //initialize this outside the loop

//inside the loop :

int temp=<given number>;
storage=storage * 10 + temp; /* this statement can be used to replace strlen() */

[Unregistered]

also, don't you mean istream.get() ?
is this better than getch() ?

[golfinguy4]

1. Input as char array
2. Find the length of the input.
3. Create a loop that goes from length minus one till zero.
4. Convert current number into an int
5. Multiply that int by 10^loop # and add it to current temp
6. Continue with loop until comple and return temp.