# convert char to int

when i use atoi, i get
implicit declaration of function `int atoi(...)'
is there any other way to convert char to int?

• : implicit declaration of function `int atoi(...)'
: --> 25: NP=atoi(readin[0]);

The function is defined like so:

int atoi(const char *string);

So, make sure you are passing it a pointer to a character array that ends with a NULL char (i.e. a string). I have no idea what readin[0] is, but if readin is a string, then you are passing it a single character, not a string.
Jason Doucette
http://www.jasondoucette.com/
"[italic]If you don't win, its not a great tragedy - the worst that happens is that you lose a game.[/italic]" - [italic]Bobby Fischer[/italic]

• : when i use atoi, i get
: implicit declaration of function `int atoi(...)'
: --> 25: NP=atoi(readin[0]);
: is there any other way to convert char to int?
:

Make sure you include right libraries?
#include
[italic][blue]To understand recursive, first you need to understand recursive[/blue][/italic]

• : : when i use atoi, i get
: : implicit declaration of function `int atoi(...)'
: : --> 25: NP=atoi(readin[0]);
: : is there any other way to convert char to int?
: :
:
: Make sure you include right libraries?
: #include
: [italic][blue]To understand recursive, first you need to understand recursive[/blue][/italic]
:
:
[green]If you really want to convert a char to an int then atoi() is the wrong way. That takes a character [b]string[/b] such as "1234" and returns the int. To change a char to an int is easily done by a cast.
[code]
int Integer;
char Character;
...
Integer = (int)Character;
[/code]

• : [green]If you really want to convert a char to an int then atoi() is the wrong way. That takes a character [b]string[/b] such as "1234" and returns the int. To change a char to an int is easily done by a cast.
: [code]
: int Integer;
: char Character;
: ...
: Integer = (int)Character;
: [/code]
:
:

[blue]Well, maybe. You're right if all you want to do is to convert a char to int with the same hex value, e.g. 'A' = 64. but if you want to convert '1' to its numeric value 1, then you need to do a little more.[/blue]
[code]
int Integer;
char Character = '1';

Integer = (int)Character[red] - '0';[/red]
[/code]

• : : [green]If you really want to convert a char to an int then atoi() is the wrong way. That takes a character [b]string[/b] such as "1234" and returns the int. To change a char to an int is easily done by a cast.
: : [code]
: : int Integer;
: : char Character;
: : ...
: : Integer = (int)Character;
: : [/code]
: :
: :
:
: [blue]Well, maybe. You're right if all you want to do is to convert a char to int with the same hex value, e.g. 'A' = 64. but if you want to convert '1' to its numeric value 1, then you need to do a little more.[/blue]
: [code]
: int Integer;
: char Character = '1';
:
: Integer = (int)Character[red] - '0';[/red]
: [/code]
:
[green]Yes indeed.[/green]

• : : : [green]If you really want to convert a char to an int then atoi() is the wrong way. That takes a character [b]string[/b] such as "1234" and returns the int. To change a char to an int is easily done by a cast.
: : : [code]
: : : int Integer;
: : : char Character;
: : : ...
: : : Integer = (int)Character;
: : : [/code]
: : :
: : :
: :
: : [blue]Well, maybe. You're right if all you want to do is to convert a char to int with the same hex value, e.g. 'A' = 64. but if you want to convert '1' to its numeric value 1, then you need to do a little more.[/blue]
: : [code]
: : int Integer;
: : char Character = '1';
: :
: : Integer = (int)Character[red] - '0';[/red]
: : [/code]
: :
: [green]Yes indeed.[/green]
:
:
WOW!
Thank you SO MUCH for this info!
You've just solved a homework problem for me! I've already put in too
much time on this, but now I can finish my code.
Thanks again!
Take care;
Dan