C - integer from string in array of chars (or array of integers?)

[dperren]

Hi.

I've just thrown myself head first into C, and am having a bit of trouble getting my head round the way the datatypes and arrays work.

At the moment, I'm working on a problem which involves a very long (1000 digit) number - I need to pick out individual digits from it, rather than use it as a whole. The idea I initially had was to do:

char n[] = "1232534654734634...";
int v = n[0]; //Presumably some type conversion needed?

But that didn't seem to work: the compiler would just throw out a 'makes pointer from integer without a cast' message.

The second idea was storing the values in an array of integers, therefore negating the need for switching between types, but I don't know how to go about it.

Could anyone help?

Thanks,

[Savage]

Hi.

I've just thrown myself head first into C, and am having a bit of trouble getting my head round the way the datatypes and arrays work.

At the moment, I'm working on a problem which involves a very long (1000 digit) number - I need to pick out individual digits from it, rather than use it as a whole. The idea I initially had was to do:

char n[] = "1232534654734634...";
int v = n[0]; //Presumably some type conversion needed?

But that didn't seem to work: the compiler would just throw out a 'makes pointer from integer without a cast' message.

The second idea was storing the values in an array of integers, therefore negating the need for switching between types, but I don't know how to go about it.

Could anyone help?

Thanks,

To convert between int and char you only need to add +'0':(ASCII code for 0)

char c='1';
int v=c+'0';

now v is 1;

Savage

[dperren]

That doesn't seem to be working unfortumately:

The code I have:

#include <stdio.h>
 
int main(void)
{
    char n[] = "731671765313306249192251196744265747"; //This keeps going for longer in the actual version
    int v = n[0];
 
    printf("%d \n", v);
}

This outputs '55'. Changing 'int v = n[0];' to 'int v = n[0]+'0'; outputs 103. Possibly the correct ascii code for the character, but not what I'm after.

I want n[0] = 7, n[1]=3, etc.

Thanks for the help so far,

[Savage]

That doesn't seem to be working unfortumately:

The code I have:

#include <stdio.h>
 
int main(void)
{
    char n[] = "731671765313306249192251196744265747"; //This keeps going for longer in the actual version
    int v = n[0];
 
    printf("%d \n", v);
}

This outputs '55'. Changing 'int v = n[0];' to 'int v = n[0]+'0'; outputs 103. Possibly the correct ascii code for the character, but not what I'm after.

I want n[0] = 7, n[1]=3, etc.

Thanks for the help so far,

Sorry my bad,you should decrease it for '0'

Savage

[dperren]

That seems to have done the trick.

Thanks for the solution :)

[Savage]

That seems to have done the trick.

Thanks for the solution :)

I'm more than happy to help you.

Savage