SLU CMPS161 Test 1

Operators

+, -, *, /, %

Two Import Statemets

Specific and Wildcard import. The specific import specifies a single class and imports it; the wildcard imports all classes in a package.

Memory

Stores data and program instructions for the CPU to execute. A memory unit is stored in a sequence of bytes. Memory is volatile.

Programming errors

Syntax, runtime, and logic. Errors reported by the compiler are syntax or compile errors. Runtime errors are errors that cause the program to terminate abnormally. Logic errors occur when a program does not perform the way it was intended to.

Computer Programming

The writing instructions (i.e. code) for computers to perform

Four integer types

Byte, short, int, long

UNIX Epoch

January 1, 1970

Computer's two stable states

zeros and ones

Increment and decrement

(++) and (--) increase or decrease a variable by 1.

Integer arithmetic

(/) Yields an integer result

CPU

(Central Processing Unit) is a computer's brain. It receives instructions from memory and executes them

Augumented Assignment Operators

+=, -=, *=, /=, and %=

Machine Language

A set of primitive instructions built into every computer

Casting

A variable of a small type to a larger range is known as widening a type. The opposite is known as narrowing a type. Widening a type may be performed automatically without explicit casting. Narrowing a type must be performed explicitly.

High-level languages

Are English-like and easy to learn and program. A program written in (blank)-level language is called a source program.

Identifiers

Are names for naming elements such as variables, constants, methods, classes, packages in a program

Variables

Are used to store data in a program. To declare a (blank) is to tell the compiler what type of data a variable can hold.

Bit

Binary digit of 0 and 1

Java source code is...

CASE SENSITIVE

Software

Computer programs that are the invisable instructions that control the hardware and make it perform tasks

Assignment operator

Equal sign (=)

.class extension

Every class is compiled into a separate byte-code file that had the same name as the class and ends with... To run a (blank) from the command line, use the java command.

Statement

Everyone ends with a semicolon (;) also known as the (blank) terminator

(Type) Value

Explicitly convert a value of one type to another

Two floating-point types

Float and double

Reserved words or keywords

Have a specific meaning to the compiler and cannot be used for other purposes in the program

Assembly Language

Is a low-level programming language in which mnemonic is used to represent each machine-language instruction

Operating System (OS)

Is a program that manages and controls a computer's activities

Compiler

Is a software program that translates the source program into machine-language program

Java

Is platform independent, meaning that you can write a program once and run it on any computer. (blank) programs can be embedded in HTML pages and downloaded by Web browsers to bring live animation and interaction to Web clients

Java source file

Name must match the public class name in the program. (blanks) must end with the .java extension. To compile from the command-line, use the javac command

Order used in Java

PEMDAS

Hardware

Physical aspect of the computer that can be touched

Named constant

Represents permanent data that never changes. Declared by using the variable final.

Identifier Criteria

Sequence of charcters that consists of letters, digits, underscores, and dollar signs. An identifier must start with a letter or underscore. It cannot start with a digit. An identifier cannot be a reserved word. An identifier can be of any lengt.

Comments

When preceded by two slashes- line comment. Enclosed between /* and */ - paragraph comment or block comment.

Storage devices

Where programs and data are permanently stored, but are moved to memory when the computer actually uses them

Methods are contained in...

a class. To run a Java program, the program must have a main method. The main method is the entry point where the program starts when it is executed

Block

begins with an opening brace { and ends with a closing brace }

Byte

is a sequence of 8 bits

Kilobyte (and other conversions)

is about 1,000 bytes, a megabyte about 1 million bytes, a gigabyte about 1 billion bytes, and a terabyte, about 1,000 gigabytes

A Variable declared in a method...

must be assigned a value before it can be used.