Chapter 2: Elementary Programming

Front 1

Algorithm

Back 1

Describes how a problem is solved by listing the actions that need to be taken and the order of their executions

Front 2

Pseudocode

Back 2

natural language mixed with some programming code

Front 3

Variable

Back 3

represents a value stored in the computer's memory

descriptive names to specify data types

Front 4

Identifiers

Back 4

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

Front 5

An identifier is

Back 5

a sequence of characters that consists of letters, digits, underscores (_), and dollar signs($)

must start with a letter or underscore

cannot start with a digit

cannot be a reserved word

cannot be true, false, or null

can be any length

Front 6

specific import

Back 6

specifies a single class in the import statement

import java.util.Scanner;

Front 7

wildcard import

Back 7

imports all the classes in a package by using the asterisk as the wildcard

import java.util.*;

Front 8

Equals sign (=)

Back 8

used as the assignment operator

Front 9

Before a variable declared in a method can be used

Back 9

it must be assigned a value

Front 10

Named constant

Back 10

represents permanent data that never changes

capitalize every letter in a constant

declared by using the keyword final

final double PI = 3.14159; // declare a constant

Front 11

4 integer types

Back 11

byte

short

int

long

Front 12

Floating point types

Back 12

Float and double

represent floating point numbers of two different precisions

real numbers (numbers with a decimal point)

Front 13

operators that perform numeric operations

Back 13

+ addition

- subtraction

* multiplication

/ division

% remainder

Front 14

Integer arithmetic yields

Back 14

an integer result

Front 15

numeric operators

Back 15

applied the same way as in an arithmetic expression

Front 16

augmented assignment operators

Back 16

+= addition assignment

-= subtraction assignment

*= multiplication assignment

/= division assignment

%= remainder assignment

Front 17

increment operator

Back 17

++

Front 18

decrement operator

Back 18

--

Front 19

When evaluating an expression with values of mixed types,

Back 19

java automatically converts operands to appropriate types

Front 20

(type)value notiation

Back 20

you can explicitly convert a value from one type to another

Front 21

Widening a type

Back 21

casting a variable of a type with a small range to a variable of a type with a larger range

can be performed automatically without explicit casting

System.out.println((double)1 / 2);

//displays 0.5 because 1 is cast to 1.0 first and then divided by 2

Front 22

Narrowing a type

Back 22

casting a variable of a type with a large range to a variable of a type with a smaller range

must be performed explicitly

System.out.println((int)1.7);

//displays 1, when a double value is cast into an int value, the fractional part is truncated

Front 23

String concatenation operator

Back 23

+

combines two strings into one

Front 24

Create a scanner

Back 24

creates an object of the scanner type

whole line:

Scanner input = new Scanner(System.in)

Front 25

Import class

Back 25

import java.util.Scanner

Scanner is in the java.util package

Front 26

read a double

Back 26

//Prompt the user to enter a radius

System.out.print("Enter a number for radius: ");

double radius = input.nextDouble();

Front 27

Prompt

Back 27

directs user to enter an input

Front 28

Print vs println

Back 28

println moves to the beginning of the next line after displaying the string, but print does not advance to the next line when completed

Front 29

Variabel declaration

Back 29

tells the compiler to allocate appropriate memory space for the variable based on its data type

Front 30

Assignment statement

Back 30

designates a value for a variable

Front 31

byte range and storage size

Back 31

-2^7 to 2^7 - 1(-128 to 127)

8-bit signed

Front 32

short range and storage size

Back 32

-2^15 to 2^15 - 1(-32768 to 32767)

16-bit signed

Front 33

int range and storage size

Back 33

-2^31 to 2^31 - 1(-2147483648 to 2147483647)

32-bit signed

Front 34

long range and storage size

Back 34

-2^63 to 2^63 - 1

64-bit signed

Front 35

float range and storage size

Back 35

Neg range: -3.4028235E + 38 to -1.4E - 45

Pos range: 1.4E - 45 to 3.4028235E + 38

32-bit IEEE 754

Front 36

double range and storage size

Back 36

Neg range: -1.79.....E + 308 to -4.9E - 324

Pos range: 4.9E - 324 to 1.79.....E + 308

64-bit IEEE 754

Front 37

Math.pow(a, b) method

Back 37

can be used to compute a^b

Systme.out.println(Math.pow(a, b));

//Displays value of a^b

Front 38

Operator precedence rule

Back 38

multiplication, division and remainder operators are applied first

if an expression contains several multiplication, division, and remainder operators, it is left to right

addition and subtraction operators are applied last

if contains several, left to right

Front 39

augmented assignment operator examples

Back 39

i += 8 ... i = i + 8

i -= 8 ... i = i - 8

i *= 8 ... i = i * 8

i /= 8 ... i = i / 8

i %= 8 ... i = i % 8

Front 40

overflow

Back 40

when a variable is assigned a value that is too large (in size) to be stored

Front 41

underflow

Back 41

when a floating point number is too small (too close to zero) to be stored