char to int - Programmers Heaven

#### Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

#### Categories

Welcome to the new platform of Programmer's Heaven! We apologize for the inconvenience caused, if you visited us from a broken link of the previous version. The main reason to move to a new platform is to provide more effective and collaborative experience to you all. Please feel free to experience the new platform and use its exciting features. Contact us for any issue that you need to get clarified. We are more than happy to help you.

# char to int

Posts: 43Member
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

• Posts: 1,444Member
: 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]
• Posts: 9,765Member ✭✭✭
atoi() is even easier, providing the string is all decimal digits -- no hex or octal.
[code]
char str[] = "1234";
int n = atoi(str);
[/code]
• Posts: 1,444Member
: 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]
• Posts: 9,765Member ✭✭✭
: [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

• Posts: 1,444Member
: : [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]
• Posts: 687Member ✭✭✭
: 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.