C 库 - iswctype() 函数

C 的wctype库iswctype()函数用于检查给定的宽字符是否具有某些属性，例如字母、数字、字母数字、可打印字符、图形字符等。

语法

以下是iswctype()函数的C库语法：

int iswctype( wint_t wc, wctype_t desc );

参数

此函数接受以下参数：

• wc − 一个类型为'wint_t'的宽字符，需要进行检查。

• desc − 类型为'wint_t'的描述符，指定要检查wc所属的字符类别。 通过调用 "wctype()" 获取。

返回值

如果wc（宽字符）具有“desc”指定的属性，则此函数返回非零值；否则返回零。

示例

以下是一个基本的C程序，用于演示iswctype()的使用。

#include <wchar.h>
#include <wctype.h>
#include <stdio.h>

int main() {
    // Wide character to check
    wchar_t wc = L'A';
    // Descriptor for alphabetic characters
    wctype_t desc = wctype("alpha");

    if (iswctype(wc, desc)) {
        wprintf(L"%lc is an alphabetic character.\n", wc);
    } else {
        wprintf(L"%lc is not an alphabetic character.\n", wc);
    }

    return 0;
}

输出

以下是输出：

A is an alphabetic character.

示例 1

让我们创建另一个C示例，并使用iswctype()来检查宽字符是否为字母数字字符。

#include <wchar.h>
#include <wctype.h>
#include <stdio.h>

int main() {
    // Wide character string to check
    wchar_t str[] = L"Tutorialspoint 500081";
    // Descriptor for alphanumeric characters
    wctype_t desc = wctype("alnum");

    // Loop through each character in the string
    for (size_t i = 0; str[i] != L'\0'; ++i) {
        // Check if the character is alphanumeric
        if (iswctype(str[i], desc)) {
            wprintf(L"%lc is an alphanumeric character.\n", str[i]);
        } else {
            wprintf(L"%lc is not an alphanumeric character.\n", str[i]);
        }
    }

    return 0;
}

输出

以下是输出：

T is an alphanumeric character.
u is an alphanumeric character.
t is an alphanumeric character.
o is an alphanumeric character.
r is an alphanumeric character.
i is an alphanumeric character.
a is an alphanumeric character.
l is an alphanumeric character.
s is an alphanumeric character.
p is an alphanumeric character.
o is an alphanumeric character.
i is an alphanumeric character.
n is an alphanumeric character.
t is an alphanumeric character.
  is not an alphanumeric character.
5 is an alphanumeric character.
0 is an alphanumeric character.
0 is an alphanumeric character.
0 is an alphanumeric character.
8 is an alphanumeric character.
1 is an alphanumeric character.

示例 2

下面的示例检查宽字符wc是否为标点符号字符并打印。

#include <wchar.h>
#include <wctype.h>
#include <stdio.h>

int main() 
{ 
   wchar_t wc = L'#';
   // checks if the character is a punctuation
   if (iswctype(wc, wctype("punct"))) 
      wprintf(L"%lc is a punctuation\n", wc); 
   else
      wprintf(L"%lc is not a punctuation\n", wc);
   return 0; 
}

输出

以下是输出：

# is a punctuation