AP Computer Science Unit 1

Program

Program

A set of commands written in a programming language to perform a task

Programming language

Structural language that allows the programmer to communicate with the computer

Machine Code

A language a computer understands that consists of commands written only in binary (0’s and 1’s)

Long Comment

Comments that go beyond one line of code

denoted with :

/* (to open the comment) and */ (to close)

Short Comment

Comment that is only one line of code

denoted with:

//

Identifiers

names that are given to show data that are stored in the memory of a computer when a program is being executed

Compiling

the process of an interpreter converting a programmers code into binary

Compiling error (Syntax Error)

a program is unable to compile due to errors in the programs code

Runtime Error

errors that happen while the program is running

Logic Error

When a program produces the incorrect output due to a flaw in the program

Structure for creating an identifier

type identifier = data

Do assignment statements print output?

NO

they simply assign data to the identifier

Variable

When data is associated with an identifier it is referred to as a .

Can a variable type change?

NO

once a variable is assigned and given a type it can NEVER be changed (for now)

Primitive Data

basic type of data; built in data types that hold a limited amount of data

int (data type)

any number that is an integer

cannot be decimals

double (data type)

any number that can be positive or negative and can be a fraction or decimal

boolean (data type)

a value that is true or false

True = 1 False = 0

char (data type)

represents a single character that can be seen on a keyboard

• letters, numbers, spaces, and special characters

Casting

treating a value as another type

Concatenation

When a string value is joined to another piece of data

Literals

basic value that can be interpreted in only one way

What does the “+” do?

addition

What does the “-” do?

Subtraction

What is “%” called and what does it do?

modulus

does the division of the variables then returns the remainder

What does the “/” do?

division

What is “++” called and what does it do?

increment operator

it increases the value of a number by one

What is “- -” called and what does it do?

decrement operator

decreases the value of a number by one