Hi!
is there a way to convert value of a string into an integer? i am doing a simultaneous equation program that needs this.

Thank you.
Abhishek
http://deydas.net

: Hi!
: is there a way to convert value of a string into an integer? i am doing a simultaneous equation program that needs this.
:
: Thank you.
: Abhishek
: http://deydas.net
:

Try strtol declared in <stdlib.h>. strtol
has the form..

long strtol(const char * s, char * *endptr, int radix);

where s is the string, endptr is a ptr
to buffer to store first non-int char, radix is
the base of the number to convert it to.

For example...

#include <cstdlib>

// convert string "123" into int
int iValue = strtol ("123\0",0 ,10);

Hope this helps;
~mt2002

atoi() is even easier, providing the string is all decimal digits -- no hex or octal.

char str[] = "1234";
int n = atoi(str);

: atoi() is even easier, providing the string is all decimal digits -- no hex or octal.
:

: char str[] = "1234";
: int n = atoi(str);
: 

:

I just want to note that atoi() isnt ANSI compatible,
however most compilers support it. I heard some GCC
compilers dont, though (I dont use GCC).

:
: I just want to note that atoi() isnt ANSI compatible,
: however most compilers support it. I heard some GCC
: compilers dont, though (I dont use GCC).
:


yes it is ansi C --

http://www.cplusplus.com/ref/cstdlib/atoi.html

: :
: : I just want to note that atoi() isnt ANSI compatible,
: : however most compilers support it. I heard some GCC
: : compilers dont, though (I dont use GCC).
: :
:
:
: yes it is ansi C --
:
: http://www.cplusplus.com/ref/cstdlib/atoi.html

Your right--I misread atoi() as itoa()!

: Hi!
: is there a way to convert value of a string into an integer? i am doing a simultaneous equation program that needs this.
:
: Thank you.
: Abhishek
: http://deydas.net
:

If you're using 0 to fill in missing terms, then sscanf will return the number of conversions instead of a value.

#include <stdio.h> 
#include <string.h>

int main(void)
{
   
   int n;
   
   printf("hex: %2d\n", sscanf("FF", "%x", &n) == 1 ? n : -1); 
   printf("oct: %2d\n", sscanf("377", "%o", &n) == 1 ? n : -1);
   printf("dec: %2d\n", sscanf("255", "%d", &n) == 1 ? n : -1); 
   
   return (0);
}  

It *should* work with dec, hex, or oct values.