C# Numeric And String Data Ch 4

Front 1

Give number of bytes, .NET structure, and description for the C# keyword:

byte

Back 1

1 byte

Byte

Positive integer from 0 to 255

Front 2

Give number of bytes, .NET structure, and description for the C# keyword:

sbyte

Back 2

1 byte

SByte

Signed integer from -128 to 127

Front 3

Give number of bytes, .NET structure, and description for the C# keyword:

short

Back 3

2 bytes

Int16

short integer from -32,768 to 32,767

Front 4

Give number of bytes, .NET structure, and description for the C# keyword:

ushort

Back 4

2 bytes

UInt16

unsigned integer from 0 to 65,535

Front 5

Give number of bytes, .NET structure, and description for the C# keyword:

int

Back 5

4 bytes

Int32

signed integer from ~ -2 billion to ~ + 2 billion

Front 6

Give number of bytes, .NET structure, and description for the C# keyword:

uint

Back 6

4 bytes

UInt32

unsigned integer from 0 to ~ + 4 billion

Front 7

Give number of bytes, .NET structure, and description for the C# keyword:

long

Back 7

8 bytes

Int64

signed integer from ~ -9 billion to ~ + 9 billion

Front 8

Give number of bytes, .NET structure, and description for the C# keyword:

ulong

Back 8

8 bytes

UInt64

unsigned integer from 0 to ~ +18 billion

Front 9

Give number of bytes, .NET structure, and description for the C# keyword:

float

Back 9

4 bytes

Single

signed float w/ 7 sig figs

Front 10

Give number of bytes, .NET structure, and description for the C# keyword:

double

Back 10

8 bytes

Double

signed float w/ 14 sig figs

Front 11

Give number of bytes, .NET structure, and description for the C# keyword:

decimal

Back 11

16 bytes

Decimal

signed float w/ 28 sig figs

Front 12

Give number of bytes, .NET structure, and description for the C# keyword:

char

Back 12

2 bytes

Char

single unicode character

Front 13

Give number of bytes, .NET structure, and description for the C# keyword:

bool

Back 13

1 byte

Boolean

on or off

Front 14

keyword to declare a constant in C#

Back 14

const

Front 15

variable naming convention for C#

Back 15

camel case

Front 16

how do you identify a literal value as a float in C#?

Back 16

append f or F

Front 17

how do you identify a literal value as a decimal in C#?

Back 17

append m or M

Front 18

Naming convention for constants in C#

Back 18

Pascal case (not all upper)

Front 19

Order of precedence for arithmetic operators in C#

Back 19

1. Increment and decrement

2. Positive and negative

3. Multiplication, division, modulus

4. Addition, subtraction

Front 20

Does C# allow implicit casting for widening conversions?

Back 20

yes, it will automatically promote but will not automatically demote

Front 21

Syntax to explicitly cast for narrowing conversion

Back 21

(type)varName

int grade = (int)myDecimal;

Front 22

Five static methods of the Math class in C#, including appropriate capitalization

Back 22

Math.Pow(int 1, int power);

Math.Round(decimal [, precision [,roundingMode]]);

Math.Sqrt(decimal);

Math.{Min|Max}(decimal1, decimal2);

Front 23

Default rounding mode in C#

Back 23

banker's rounding: if you round a decimal that ends in 5, it is rounded to the nearest even decimal value

Front 24

create a new string that concatenates string1 and "a"

Back 24

string newString = string1 + "a";

Front 25

Any difference in escape sequences for C#?

Back 25

no

Front 26

verbatim string literal

Back 26

lets you use characters that would normally require an escape sequence without using an escape sequence. Prepend with @ and enclose in double quotes

string path = @"c:\c#\files";

Front 27

How do you enter double quotes within a verbatim string literal?

Back 27

double double quotes

string x = @"Enter ""x"" ";

Front 28

structure vs. class in C#

Back 28

structure: variables are value types. Each variable retains its own copy

class: variables are reference types. Does not store the data itself. Each variable contains a reference to the area of memory where the reference is stored

Front 29

When you use a C# keyword like double or string, what are you actually doing?

Back 29

using an alias for the associated data structure or class

Front 30

is double a C# keyword for a structure or a class? Is it a value type or a reference type?

Back 30

.NET structure: Double

value-type

Front 31

is string a C# keyword for a structure or a class? Is it a value type or a reference type?

Back 31

.NET class: String

reference type

Front 32

can two or more variables refer to the same double object? What about the same string object?

Back 32

double: no. they each store their own copy

string: yes. it's a reference type (class), not a value-type (structure)

Front 33

method to convert to a string

Back 33

myString.ToString([format]);

//format is optional

Front 34

static method that converts the specific string to to an equivalent data value. If the string can't be converted, an exception occurs.

Back 34

Integer.Parse(myString);

Double.Parse(myString);

etc.

Front 35

static method that converts the specified string to an equivalent data value and stores it in the result variable. Returns a true value if the string is converted. Otherwise, returns a false value.

Back 35

bool wasConverted = Decimal.TryParse(myString, out resultVar)

Front 36

Conversion statements using the Convert class

Back 36

//static methods for converting to built-in types

Convert.ToString(myDecimal);

Convert.ToDecimal(myString);

Convert.ToInt32(myString);

Convert.ToInt16(myString);

Convert.ToBool(value);

Front 37

Standard numeric formatting codes:

Formats the number as current with the specific number of decimal places

Back 37

Currency

C or c with number appended

Front 38

Standard numeric formatting codes:

Formats the number as a percent with the specified number of decimal places

Back 38

Percent

P or p with number appended

Front 39

Standard numeric formatting codes:

Formats the number with thousands separators and the specified number of decimal places

Back 39

Number

N or n with number appended

Front 40

Standard numeric formatting codes:

Formats the number as a decimal with the specified number of decimal places:

Back 40

Float

F or f with number appended

Front 41

Standard numeric formatting codes:

Formats an integer with the specified number of digits

Back 41

Digit

D or d with number appended

Front 42

Standard numeric formatting codes:

Formats the number in scientific (exponential) notation with the specified number of decimal places

Back 42

Exponential

E or e with number appended

Front 43

Standard numeric formatting codes:

Formats the number as a decimal or in scientific notation depending on which is more compact

Back 43

General

G or g with number appended

Front 44

Where can you declare variables with class scope?

Back 44

After the code that is generated for a form

(After InitializeComponent())

Front 45

enumeration

Back 45

set of related constants that define a value type where each constant is known as a member of the enumeration

Front 46

What are enumerations provided by the .NET framework generally used for?

Back 46

setting object properties and specifying the values passed to methods

Front 47

Give an example of a common enumeration provided by the .NET framework

Back 47

FormBorderStyle.FixedDialog

FormBorderStyle.FixedSingle

FormBorderStyle.Sizable

this.FormBorderStyle = FormBorderStyle.FixedSingle;

//normally you would use the properties window to code this

Front 48

When does it make sense to write your own enumeration?

Back 48

When a user needs to select one option from a group of related options. Create an enumeration to keep them together

Front 49

Syntax to create an enumeration of shorts. What is the default data type if you leave out short? What are the default values if you don't assign values?

Back 49

enum MyTerms : short {

Net30Days = 30,

Net60Days = 60,

Net90Days = 90

}

default data type: int

default values: 0, 1, 2 (whatever indexes would be)

Front 50

How do you refer to an enumerator constant?

Back 50

EnumerationName.MemberName

Front 51

How do you refer to the name of the constant in the enumeration instead of its value?

Back 51

EnumerationName.MemberName.ToString();

Front 52

In C#, can value types store null values? What about reference types?

Back 52

Value types: no, not by default. Must use nullable types

References types: yes

Front 53

How do you declare a nullable type?

Back 53

Question mark after type

double? myDouble = null;

Front 54

Once you've declared a nullable type, how do you check if it has a value? How to do you get the value?

Back 54

myNum.HasValue()

myNum.Value()

Front 55

null coalescing operator

Back 55

??

Returns value of left operator if not null and value of right operator if it is

int? quantity = null;

quantity ?? = 52;