字符由char类型表示,只能容纳256个不同的值。
| 类型 | 存储空间 | 用途 |
|---|---|---|
| char | 1个字节 | UTF-8代码单元 |
| wchar | 2个字节 | UTF-16代码单元 |
| dchar | 4个字节 | UTF-32代码单元和Unicode代码点 |
下面列出了一些有用的字符函数-
isLower - 确定是否使用小写字符
isUpper - 确定是否大写字符
isAlpha - 确定是Unicode字母数字字符(通常是字母还是数字)
isWhite - 确定是否有空格字符
toLower - 产生给定字符的小写字母
toUpper - 产生给定字符的大写字母
import std.stdio; import std.uni; void main() { writeln("Is ğ lowercase? ", isLower(ğ)); writeln("Is Ş lowercase? ", isLower(Ş)); writeln("Is İ uppercase? ", isUpper(İ)); writeln("Is ç uppercase? ", isUpper(ç)); writeln("Is z alphanumeric? ", isAlpha(z)); writeln("Is new-line whitespace? ", isWhite( )); writeln("Is underline whitespace? ", isWhite(_)); writeln("The lowercase of Ğ: ", toLower(Ğ)); writeln("The lowercase of İ: ", toLower(İ)); writeln("The uppercase of ş: ", toUpper(ş)); writeln("The uppercase of ı: ", toUpper(ı)); }
编译并执行上述代码后,将产生以下输出-
Is ğ lowercase? true Is Ş lowercase? false Is İ uppercase? true Is ç uppercase? false Is z alphanumeric? true Is new-line whitespace? true Is underline whitespace? false The lowercase of Ğ: ğ The lowercase of İ: i The uppercase of ş: Ş The uppercase of ı: I
读取字符
我们可以使用 readf 读取字符,如下所示。
readf(" %s", &letter);
由于D编程支持unicode,因此为了读取unicode字符,我们需要读取两次并写入两次才能获得预期的输出。该如下所示。
import std.stdio;void main() { char firstCode; char secondCode;
write("Please enter a letter: "); readf(" %s", &firstCode); readf(" %s", &secondCode);
writeln("The letter that has been read: ", firstCode, secondCode); }
编译并执行上述代码后,将产生以下输出-
Please enter a letter: ğ The letter that has been read: ğ