C++ <clocale> - LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME

The C++ <clocale> contains LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, LC_NUMERIC, LC_TIME macro constants. Each of these macro constants expand to integer constant expressions with distinct values that are suitable for use with setlocale() function as the first argument.

Macros	Description
LC_ALL	Selects the entire C locale.
LC_COLLATE	Selects the collation category of the C locale.
LC_CTYPE	Selects the character classification category of the C locale.
LC_MONETARY	Selects the monetary formatting category of the C locale.
LC_NUMERIC	Selects the numeric formatting category of the C locale.
LC_TIME	Selects the time formatting category of the C locale.

Definition in the <clocale> header file is:

#define LC_ALL      /* implementation defined */
#define LC_COLLATE  /* implementation defined */
#define LC_CTYPE    /* implementation defined */
#define LC_MONETARY /* implementation defined */
#define LC_NUMERIC  /* implementation defined */
#define LC_TIME     /* implementation defined */

Example:

The example below shows the usage of these macros.

#include <cstdio>
#include <ctime>
#include <clocale>
 
int main (){
  time_t t = time(NULL);
  char buffer [80];

  printf("Local is: %s\n", setlocale(LC_ALL,"C"));

  //monetary formatting will be US
  setlocale(LC_MONETARY, "en_US.UTF-8");  
  struct lconv *lc = localeconv();

  printf("Local Currency Symbol: %s\n", 
          lc->currency_symbol);

  //time formatting will be environment's 
  //default locale
  setlocale(LC_TIME, ""); 
  strftime (buffer,80,"%c",localtime(&t));
  printf("Date is: %s\n", buffer);

  return 0;
}

The output of the above code will be:

Local is: C
Local Currency Symbol: $
Date is: Mon May 10 07:41:59 2021

❮ C++ <clocale> Library