isdigit


function template
<locale> 
template <class charT>
  bool isdigit ( charT c, const locale& loc );

Check if character is a decimal digit using locale

Checks whether c is a decimal digit using ctype facet of locale loc, returning the same as a call to:

  
use_facet < ctype<charT> > (loc).is (ctype_base::digit, c)


This function replicates the functionality of its C-library equivalent isdigit. See isdigit for more info.

Parameters

c
Character to be checked.
loc
Locale to be used. Shall have facet ctype present.


Template parameter charT is the character type.

Return Value

true if indeed c is a decimal digit character, false otherwise.

Example

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// isdigit example (C++)
#include <iostream>
#include <string>
#include <sstream>
#include <locale>
using namespace std;

int main ()
{
  locale loc;
  string str="1776ad";
  if ( isdigit(str[0],loc) )
  {
    int year;
    stringstream(str) >> year;
    cout << "The year that followed " << year << " was " << (year+1) << ".\n";
  }
  return 0;
}


Output:

The year that followed 1776 was 1777.


See also

ctype Character type facet (class template)
isdigit (cctype) Check if character is decimal digit (function)
isalnum Check if character is alphanumeric using locale (function template)
isalpha Check if character is alphabetic using locale (function template)