Java Language Fundamentals

Java Language Fundamentals

1. Encoding Sets

   • Java supports the Unicode character set, which allows for text to be written using characters from any language
     • Since Unicode stores so many characters, transmitting Unicode text is not efficient
       • Solution: Character encoding! (a.k.a data compression)
         • UTF-8 Encoding
           • UTF-8 translates any character into a binary string. The string can be 1-4 bytes, and the first 256 most commonly used ASCII characters are all stored in one byte
             • By using less space to store more common characters, UTF-8 reduces file size and allows for a large number of less-common characters

2. Primitives

   • Simple, non-object programming elements, represent numbers and boolean values (t/f)

3. Variables

   • Data placeholders whose contents can change
     • Each variable has a type and a name/identifier
       • Syntax: type name;

4. Constants

   • Variables whose values cannot be changed after initial assignment
     • To Declare: Use keyword 'final'. Also, the name of a constant is usually fully capitalized, with words separated by underscores

5. Literals

   • Representation of data values understood by the Java compiler
     • Literals of Type Primative
       • Integer Literals
         • Used to assign values of variable type byte, short, int, long
           • To assign a value to a long, suffix the number with 'L'. Otherwise, the value will be considered an int.
           • Other literal assignment tips:
             • To express a literal in binary, prefix the binary number with 0B
             • To make a long integer literal easier to read, utilize underscores
       • Floating-Point Literals
         • A floating point number consists of four parts: whole number, decimal, fractional, and an optional exponent
           • There are two types of floating-point numbers: floats and doubles
             • To assign a literal as a float, suffix the number with f_or_F
       • Character Literals
         • Unicode character or escape sequence enclosed in singular quotes (ex. 'a')
           • Escape Sequences- need to write character representation (ex. '\t')
       • Boolean Literals
         • two possible values: true or false

6. Common Separators

Imagens e arquivos do mapa