Keil Logo

atoi

Summary
#include <stdlib.h>

int atoi (
  const unsigned char *string);   /* string to convert */
Description

The atoi function converts string into an integer value. The input string must be a sequence of characters that can be interpreted as an integer. This function stops processing characters from string at the first one it cannot recognize as part of the number.

The string passed to atoi must have the following format:

〚whitespace〛〚{+|-}〛 digits

Where

whitespace

May be any number of space(' '), tab ('\t'), newline ('\n'), or carriage return ('\r') characters.

digits

May be one or more decimal digits.
Return Value

The atoi function returns the integer value that is produced by interpreting the characters in string as a number.

If no conversion could be performed, 0 is returned.

See Also

atof, atol

Example
#include <stdlib.h>
#include <stdio.h> /* for printf */

void tst_atoi (void) {
  int i;
  char s [] = "12345";

  i = atoi (s);
  printf ("ATOI(%s) = %d\n", s, i);
}
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.