#include stdlib.h>
double atof(const char &sstarf#star;str); Return double value of number presented in str.
int atoi(const char &sstarf#star;str); Return int value of number presented in str.
long atol(const char &sstarf#star;str); Return long value of number presented in str.
int abs(int val); long labs(long val); Return absolute value of val.
long strtol(const char &sstarf#star;nptr, char &sstarf#star;&sstarf#star;endptr, int base); unsigned long strtoul(const char &sstarf#star;nptr, char &sstarf#star;&sstarf#star;endptr, int base); Return the value of the number in nptr with base putting the endaddress of the numerical string into endptr.
double strtod(const char &sstarf#star;nptr, char &sstarf#star;&sstarf#star;endptr); Return the double value of the number in nptr putting the endaddress of the numerical string into endptr.
#include support.h>
char &sstarf#star;_itoa(int val, char &sstarf#star;buf, int radix); char &sstarf#star;_ltoa(long val, char &sstarf#star;buf, int radix); char &sstarf#star;_ultoa(unsigned long val, char &sstarf#star;buf, int radix); Convert the value val to a string in buf according to radix.
#include locale.h>
struct lconv &sstarf#star;localeconv(); Get rules of the current locale
char &sstarf#star;setlocale(int category , const char &sstarf#star;name); Define locale named in name.