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:
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use_facet < ctype<charT> > (loc).is (ctype_base::alnum, c)
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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;
}
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Output:
The first 4 characters are alphanumeric.
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See also
| ctype | Character type facet (class template) |
| isalpha | Check if character is alphabetic using locale (function template) |
| isdigit | Check if character is a decimal digit using locale (function template) |
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