isalnum


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

Check if character is alphanumeric using locale

Checks whether c is an alphanumeric character using ctype facet of locale loc, returning the same as a call to:

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


This function replicates the functionality of its C-library equivalent isalnum. See isalnum 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 an alphanumeric character, false otherwise.

Example

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

int main ()
{
  locale loc;
  string str = "c3po...";
  size_t i=0;
  while ( (i<str.length()) && (isalnum(str[i])) ) {++i;}
  cout << "The first " << i << " characters are alphanumeric.\n";
  return 0;
}


Output:

The first 4 characters are alphanumeric.


See also