'int' and 'String' - Basic Data Types for Unicode

Unicode Tutorials - Herong's Tutorial Examples

∟'int' and 'String' - Basic Data Types for Unicode

This section provides an introduction on basic data types for storing Unicode characters in the full range of U+0000 to U+10FFFF: 'int' for a single Unicode character; 'String' for a sequence of Unicode characters.

As we learned from the previous section, the primitive type "char" is no longer capable to support Unicode characters in the full range of U+0000 to U+10FFFF. The best way to write Unicode-friendly Java applications with J2SE 5.0 or higher is to:

Always use "int" primitive type to store a single Unicode character.
Always use "String" class type to store a sequence of Unicode characters.

Other primitive types and class types can still be used to help managing Unicode characters, but you need to remember their risks and limitations:

"byte" primitive type can only support ASCII characters in the range of U+0000 to U+00FF.
"char" primitive type can only support BMP (Basic Multilingual Plane) characters in the range of U+0000 to U+FFFF.
"Character" class type can only support BMP (Basic Multilingual Plane) characters in the range of U+0000 to U+FFFF.
"char[]" array type should only be used to store UTF-16BE encoded "char" sequences of Unicode characters.

Examples of using Unicode-friendly data types:

   int letterC = 0x43; // ASCII character
   int degreeCelsius = 0x2103; // BMP character
   int squaredC = 0x1F132; // Supplementary character

   StringBuilder buffer = new StringBuilder();
   buffer.appendCodePoint(letterC);
   buffer.appendCodePoint(degreeCelsius);
   buffer.appendCodePoint(squaredC);
   String unicodeString = new String(buffer);