Java

• Developed by Sun Micro-Systems
• First programming language that wasn't tied to an operating system or hardware
• General purpose programming language

JVM (Java Virtual Machine)

• Programs are compiled into Bytecode
• The Java Virtual Machine is an interpreter that executes Bytecode

Programs

• Every program must have at least one class
  • All other code is inside that class
• Program always begins executing at the main method
  • main must always be defined in the same way

Data Types

Keyword	Size	Description	Value
byte	1 byte	Byte-length integer	$-128$ to $127$
short	2 bytes	Short integer	$-32768$ to $32767$
int	4 bytes	Integer	$-2147483648$ to $214748364$
long	8 bytes	Long integer	$-2^{63}$ to $2^{63} - 1$
float	4 bytes	Single-precision floating point
double	8 bytes	Double-precision floating point
char	2 bytes	A single character	All characters
boolean	N/A	A Boolean value	True or false

Computer Science Programming Language