Converting string to int.

I wish to convert a string to an int. The string may contain digits (0-9), a negative sign (-), or a decimal point (.). Is there a function to handle this? Can you be quickly written? Btw, I can either use c-style char * strings, or STL strings.

atoi()

atoi() for null terminated strings.

toInt() or some such function for STL strings.

Ever tried type casting??

Code:

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char my_string [1];
cout << "my_string: " << my_string;
cout << "int(my_string): " << int(my_string);

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I think that's it :)
Good Luck :)

Code:

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char my_string [1];

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initialize it dude....

char mychar = 'a';

int (mychar) works... strange... but most
books say (int)mychar for typecasting...

Thanks guys... so what you suggested will handle non digit characters such as the negative sign and decimal point, right?

i think atoi() is better than typecasting the thing.
so use atoi()

>i think atoi() is better than typecasting the thing.
>so use atoi()

I agree with moonwalker.

Quote:

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Originally posted by moonwalker

Code:

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char my_string [1];

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initialize it dude....

char mychar = 'a';

int (mychar) works... strange... but most
books say (int)mychar for typecasting...

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Ok :) Whatever you say :)

>atoi() for null terminated strings.
atoi is notorious for causing problems and most experienced programmers place it with gets to be removed from the language at the first chance. The problem is in how it handles errors, it's far better to use strtol and cast the result to int. Another option is to use sscanf or stringstreams to read an integer value from a C-string or C++ string to an int variable.

-Prelude

Hey, can you make type casting in C ??

int one;

double two = 2.0;

one = (int)two;

c style type casting. Look up dynamic_cast<>, static_cast<>, etc. for c++ style casting.

Quote:

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Originally posted by Ruski
Hey, can you make type casting in C ??

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oh sure, it will let you, in fact C will let you write just about anything you want ("who cares what it means? i just compile it", said the compiler) :p :D

but this:

Code:

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#include <stdio.h>

int main (void)
{
  char mystring[] = "46";
  int i;
  i = (int) mystring;
  printf ("%i\n", i);
  return 0;
}

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means something totally different than what you're looking for. (and no, the program doesn't print out 46 when run)

Thanks for the reply :)