isdigit

测试一个元素在区域设置是否是一个数字字符。

template<Class CharType>
   bool isdigit(
      CharType _Ch, 
      const locale& _Loc
   )

参数

• _Ch
  要测试的元素。

• _Loc
  包含元素的区域设置是测试。

返回值

true，如果测试的组件是一个数字字符; false，如果未启用。

备注

模板函数返回 use_facet<ctype<CharType> > (_Loc)。是(ctype<CharType>::digit，_Ch)。

示例

// locale_is_digit.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>

using namespace std;

int main( )   
{
   locale loc ( "German_Germany" );
   bool result1 = isdigit ( 'L', loc );
   bool result2 = isdigit ( '@', loc );
   bool result3 = isdigit ( '3', loc );

   if ( result1 )
      cout << "The character 'L' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character 'L' in the locale is "
           << " not a numeric character." << endl;

   if ( result2 )
      cout << "The character '@' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character '@' in the locale is "
           << " not a numeric character." << endl;

   if ( result3 )
      cout << "The character '3' in the locale is "
           << "a numeric character." << endl;
   else
      cout << "The character '3' in the locale is "
           << " not a numeric character." << endl;
}

Output

The character 'L' in the locale is  not a numeric character.
The character '@' in the locale is  not a numeric character.
The character '3' in the locale is a numeric character.

要求

标头: <locale>

命名空间: std