Encoding sets

Encoding sets

1. What programs use to represent characters in computers

   • Java currently uses Unicode, which includes all characters from all languages, for its comments, identifiers, and contents of characters/strings.
     • Java uses ASCII, which uses largely latin characters and such, for input elements

2. Separators

3. Primitives

   • Data type used in Java
     • 8 types
       • • First 6 are different ways to represent numbers, just in different sizes.
           • Want to use smallest primitive possible for efficiency
           • char is used for a single Unicode character
           • boolean has two states: true or false
   • Variables
     • Data placeholders
     • Each must have a declared type
       • Either reference or primitive
         • Reference refers to other object
         • Primitive holds a primitive
     • Must have a name or an identifier
       • Unlimited length java characters, beginning with a java letter
       • Must not be a java keyword, a boolean literal, or the null literal
       • "Must be unique within its scope"
     • You declare a variable by writing the type first, followed by the name, ending with a semi colon

4. Constants

   • Variables with values which, after being signed, are permanent
   • declare a constant by using keyword "final"
   • All caps, with words being seperated by underscores

5. Integer literals

   • assigns values to variables of byte, short, int, and long
   • To assign a value to a long, suffix the number with L or 1 at the end
   • Floating point literals
     • number has:
       • whole number part
       • decimal point
       • fractional part
       • optional exponent
     • f_or_F means float. otherwise, double
     • boolean literal
       • either true or false
       • character literal
         • single quotes
         • an escape sequence represents something that can not be entered using the keyboard or that has a special function in Java.

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