PR1 computer science

im gonna die

block comment

the compiler will ignore any text between /* */

class declaration

• identifies name, start, and end of the class

• class name MUST match file name

main method

controls all the action in the program

System.out

object that generates output to console

output

• what the computer makes from the input

• what comes out as a result of the code

console

where the output is printed

System.out.print

• display whatever is in () on screen but wait at the end of the line for more info to display

System.out.println

• display () and move cursor to the next line

compiler

translates the code in the IDE into the output in the console

what kind of programming language is Java

a compiler and interpreter

primitive types

most basic data structure in Java

determines size and type of information

types of primitive types

• int

• boolean

• char

• double

• float

• byte

string literal

an exact sequence of characters enclosed in “ “

• not a primitive type

int

represents an integer with up to 2 bil places

boolean

true/false

1 bit; smallest value

double

decimal value up to 15 places

64 bits

float

decimal value up to 6 places

char

character

*c*

syntax/compiler errors

identified when program is compiled

exception/runtime error

occurs while program is running → program terminates abnormally

logic errors

detected after program is run

actual output =/= anticipated output

differences between primitive and non-primitive types

1. primitive types already exist in Java; non-primitive is hand-made

2. non-primitive can use methods to perform actions, primitive can’t

variable

a name given to a memory location that holds a specific type of value

type

set of values (a domain) and a set of operations on them

constant/final var

cannot be changed once given a value

compound assignment operators

• used in place of “=”

• adds a value onto the stated variable

x += 7;

7 will be added onto x

increment/decrement operators

• ++ adds 1 to the value of a variable/array element

• - - subtracts 1

Java is __ oriented

object

object-oriented

organizes software design around data and objects, not functions and logic (i.e. python)

interpreter

translates code line by line