char to int

Comments

• MT2002

  February 2006

  : 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
  :
  [blue]
  Try [b]strtol[/b] declared in . [b]strtol[/b]
  has the form..
  
  long strtol(const char * s, char * *endptr, int radix);
  
  where [b]s[/b] is the string, [b]endptr[/b] is a ptr
  to buffer to store first non-int char, [b]radix[/b] is
  the base of the number to convert it to.
  
  For example...[/blue][code]
  #include
  
  [green]// convert string "123" into int[/green]
  int iValue = strtol ("123",0 ,10);[/code][blue]
  Hope this helps;
  ~mt2002[/blue]
  
• stober

  February 2006

  atoi() is even easier, providing the string is all decimal digits -- no hex or octal.
  [code]
  char str[] = "1234";
  int n = atoi(str);
  [/code]
  
• MT2002

  February 2006

  : atoi() is even easier, providing the string is all decimal digits -- no hex or octal.
  : [code]
  : char str[] = "1234";
  : int n = atoi(str);
  : [/code]
  :
  [blue]
  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).[/blue]
  
• stober

  February 2006

  : [blue]
  : 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).[/blue]
  :
  
  
  yes it is ansi C --
  
  http://www.cplusplus.com/ref/cstdlib/atoi.html
  
  
• MT2002

  February 2006

  : : [blue]
  : : 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).[/blue]
  : :
  :
  :
  : yes it is ansi C --
  :
  : http://www.cplusplus.com/ref/cstdlib/atoi.html
  [blue]
  Your right--I misread atoi() as itoa()! :-)[/blue]
  
• pseudocoder

  February 2006

  : 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.
  
  [code]
  #include
  #include
  
  int main(void)
  {
  
  int n;
  
  printf("hex: %2d
  ", sscanf("FF", "%x", &n) == 1 ? n : -1);
  printf("oct: %2d
  ", sscanf("377", "%o", &n) == 1 ? n : -1);
  printf("dec: %2d
  ", sscanf("255", "%d", &n) == 1 ? n : -1);
  
  return (0);
  }
  
  [/code]
  It *should* work with dec, hex, or oct values.