Language Fundamentals

Language Fundamentals

1. ASCII and Unicode

   • ASCII: has 128 characters
     • more efficient
   • Unicode: has 256 characters
     • not as efficient
   • Separators
     • ()parantheses, {}braces, []brackets, <>angle brackets, ;semicolon, :colon, ,comma, .period

2. Primitives

   • a data type
   • there are 8 primitive types, each with a specific format and size
   • byte, short, int, long, float, double, char, boolean
     • int is an placeholder

3. Variables

   • data placeholders
   • two data types: reference types and primitive types
     • reference types: provides a reference to an object
     • primitive types: holds a primitive
   • has a name/identifier: this must be unique

4. Constants

   • declare by the word "final"
   • constant names are in all CAPS and words separated by underscores
     • ex) final int ROW_COUNT = 50;

5. Literals

   • when assigning number 2 to an int or character 'c' to a char
     • need to write the value representation in a format that the Java complier understands
   • three types of literals: primitive types, string literals, and null literal
     • primitive types have 4 subtypes: integer literals, floating point literals, character literals, and boolean literals
       • boolean literals: true and false
       • character literals: a Unicode character or an escape sequence in single quotes ex) "\t"
       • floating point literals: a whole number part, a decimal point, a fractional part, an optional exponent
       • integer literals: assign values to variables of types byte, short, int, and long