CS1301 Unit 2

variable

used to store data like letters and numbers

value

number, letter, or other data item in a variable

variable declaration

declaring the variable’s data type (int, string, etc)

int

integer

double

numbers with decimals

char

any one character on the keyboard

class type

data type for objects of a class (Strings)

primitive type

simpler than objects, a single number or letter (int, double, char)

float (floating-point number)

number with fractions (decimals, ex: 5.0, 5.1120831)

boolean

true/false

identifier

technical term for name in programming language (letters, digits 0-9, underscore)

keywords (reserved words)

words with special meanings that cannot be used as variables/classes/mehtods (primitive words + if)

constant (literal)

terms that have unchanging values

final double

a double value that cannot be changed because of “final”

type cast

changes data type of a value from normal type to another type (ex: double to int)

operands

variables and numbers

unary operator

operators with only one operand (one thing it applies to, ex: balance = -cost)

binary operator

2 operands (ex: total = cost + tax)

I/O

Input/Output

nextInt

reads an int value

nextDouble

reads a double

next

reads a word

delimiter

separators by whitespace characters and/or line breaks

nextLine

reads the entire line

printf

print + special instructions

empty string

string with 0 characters (““)

concatenation

joining 2 strings with a + operator

index

a position in a string

substring

portion of a string

escape sequences/characters

special characters that escape the usual meaning of a character

character set

list of characters

unicode

ASCII character set + many characters used in other languages than english

=

assignment operator

+ , -

arithmetic operators, combine variables and numbers

*

multiplication

/

division

%

remainder operator

++

increment operator

- -

decrement operator

(-+/%*)=

specialized assignment operators (variable (-+/%*) something)