unit 1 - getting started and primitive types

Variable

Variable

A name associated with a memory location in the computer.

boolean

used to declare a variable that can only have the value true or false.

double

used to declare a variable that is a decimal number like 3.25.

int

used to declare a variable of type integer (a whole number like -3 or 235).

static

means that the field or method exists in the object that defines the class.

compiler

Software that translates the Java source code into the Java class file that can be run.

compiler or syntax error

An error or bug that is found by the compiler like a missing semicolon

Main Method

Where execution starts in a Java program.

Boolean

An expression that is either true or false.

Camel Case

One way to create a variable name by appending several words together and uppercasing the first letter of each word after the first word (myScore).

Casting a Variable

Changing the type of a variable using (type) name.

System.out.println()

Java method that lets us print out a line of output followed by a newline to the user

Declare a Variable

Specifying the type and name for a variable. This sets aside memory for a variable of that type and associates the name with that memory location.

Initializing a Variable

The first time you set the value of a variable.

String literal

Text enclosed by double quotes.

modulo

The % operator which returns the remainder from one number divide by another.

Operator

Common mathematical symbols such as + for addition and * for multiplication.

Shortcut or compound assignment operators

Operators like x++ or x+= 1 which mean x = x + 1

assignment statements

initialize or change the value stored in a variable using the assignment operator =.

data type

determines the size of memory reserved for a variable, for example int, double, boolean, String.

ArithmeticException

If you divide by zero, you will get this error.

operator precedence

Some operators are done before others, for example *, /, % have precedence over + and -, unless parentheses are used.

arithmetic expression

a sequence of operands and operators that describe a calculation to be performed, for example 3*(2 + x)

increment operator

The operator (++) that increases the value of a numerical variable by one.