Lec 23 Memory Maps Primitive variables and Reference (object) variables.
02. Primitive Data Types and Variables
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Transcript of 02. Primitive Data Types and Variables
Primitive Data Primitive Data Types and Types and VariablesVariables
Creating and Running Your First C# Creating and Running Your First C# ProgramProgram
Svetlin NakovSvetlin NakovTelerik Telerik
CorporationCorporationwww.telerik.com
Table of ContentsTable of Contents
1.1. Primitive Data TypesPrimitive Data Types Integer Integer Floating-Point / Decimal Floating-PointFloating-Point / Decimal Floating-Point BooleanBoolean CharacterCharacter StringString ObjectObject
2.2. Declaring and Using VariablesDeclaring and Using Variables IdentifiersIdentifiers Declaring Variables and Assigning Declaring Variables and Assigning
ValuesValues LiteralsLiterals
3.3. NullableNullable types types 2
Primitive Data Primitive Data TypesTypes
How Computing Works?How Computing Works?
Computers are machines that Computers are machines that process dataprocess data
Data is stored in the computer Data is stored in the computer memory in memory in variablesvariables
Variables have Variables have namename, , data type data type and and valuevalue
Example of variable definition and Example of variable definition and assignment in C#assignment in C#int count = 5;int count = 5;Data Data
typetype
Variable nameVariable name
Variable Variable valuevalue 4
What Is a Data Type?What Is a Data Type? A A data typedata type::
Is a domain of values of similar Is a domain of values of similar characteristicscharacteristics
Defines the type of information stored Defines the type of information stored in the computer memory (in a variable)in the computer memory (in a variable)
Examples:Examples:
Positive integers: Positive integers: 11, , 22, , 33, , ……
Alphabetical characters: Alphabetical characters: aa, , bb, , cc, , ……
Days of week: Days of week: MondayMonday, , TuesdayTuesday, , ……5
Data Type Data Type CharacteristicsCharacteristics
A data type has:A data type has: Name (C# keyword or .NET type)Name (C# keyword or .NET type) Size (how much memory is used)Size (how much memory is used) Default valueDefault value
Example:Example: Integer numbers in C#Integer numbers in C# Name: Name: intint Size: 32 bits (4 bytes)Size: 32 bits (4 bytes) Default value: 0Default value: 0
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Integer TypesInteger Types
What are Integer What are Integer Types?Types?
Integer types:Integer types: Represent whole numbersRepresent whole numbers
May be signed or unsignedMay be signed or unsigned
Have range of values, depending on Have range of values, depending on the size of memory usedthe size of memory used
The default value of integer types The default value of integer types is:is: 00 – for integer types, except – for integer types, except
0L0L – for the – for the longlong type type8
Integer TypesInteger Types Integer types are:Integer types are:
sbytesbyte (-128 to 127): signed 8-bit (-128 to 127): signed 8-bit
bytebyte (0 to 255): unsigned 8-bit (0 to 255): unsigned 8-bit
shortshort (-32,768 to 32,767): signed 16- (-32,768 to 32,767): signed 16-bitbit
ushortushort (0 to 65,535): unsigned 16-bit (0 to 65,535): unsigned 16-bit
intint (-2,147,483,648 to (-2,147,483,648 to 2,147,483,647): signed 32-bit2,147,483,647): signed 32-bit
uintuint (0 to 4,294,967,295): unsigned (0 to 4,294,967,295): unsigned 32-bit32-bit
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Integer Types (2)Integer Types (2) More integer types:More integer types:
longlong (-9,223,372,036,854,775,808 to (-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807): signed 9,223,372,036,854,775,807): signed 64-bit64-bit
ulongulong (0 to (0 to 18,446,744,073,709,551,615): 18,446,744,073,709,551,615): unsigned 64-bitunsigned 64-bit
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Measuring Time – ExampleMeasuring Time – Example
Depending on the unit of measure Depending on the unit of measure we may use different data types:we may use different data types:
byte centuries = 20; // Usually a small byte centuries = 20; // Usually a small numbernumber
ushort years = 2000;ushort years = 2000;
uint days = 730480;uint days = 730480;
ulong hours = 17531520; // May be a very big ulong hours = 17531520; // May be a very big numbernumber
Console.WriteLine("{0} centuries is {1} years, Console.WriteLine("{0} centuries is {1} years, or {2} days, or {3} hours.", centuries, years, or {2} days, or {3} hours.", centuries, years, days, hours);days, hours);
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Integer TypesInteger TypesLive DemoLive Demo
Floating-Point and Floating-Point and Decimal Floating-Decimal Floating-
Point TypesPoint Types
What are Floating-Point What are Floating-Point Types?Types?
Floating-point types:Floating-point types:
Represent real numbersRepresent real numbers
May be signed or unsignedMay be signed or unsigned
Have range of values and different Have range of values and different precision depending on the used precision depending on the used memorymemory
Can behave abnormally in the Can behave abnormally in the calculationscalculations
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Floating-Point TypesFloating-Point Types Floating-point types are:Floating-point types are:
float float (±1.5 × 10(±1.5 × 10−45−45 to ±3.4 × 10 to ±3.4 × 103838): ): 32-bits, precision of 7 digits32-bits, precision of 7 digits
double double (±5.0 × 10(±5.0 × 10−324−324 to to ±1.7 × 10±1.7 × 10308308): 64-bits, precision of ): 64-bits, precision of 15-16 digits15-16 digits
The default value of floating-point The default value of floating-point types:types: Is Is 0.0F0.0F for the for the floatfloat typetype
Is Is 0.0D0.0D for the for the doubledouble typetype15
PI Precision – ExamplePI Precision – Example See below the difference in precision when See below the difference in precision when
using using floatfloat and and doubledouble::
NOTE: The “NOTE: The “ff” suffix in the first statement!” suffix in the first statement!
Real numbers are by default interpreted as Real numbers are by default interpreted as
doubledouble!!
One should One should explicitlyexplicitly convert them to convert them to floatfloat
float floatPI = 3.141592653589793238f;float floatPI = 3.141592653589793238f;double doublePI = 3.141592653589793238;double doublePI = 3.141592653589793238;Console.WriteLine("Float PI is: {0}", Console.WriteLine("Float PI is: {0}", floatPI);floatPI);Console.WriteLine("Double PI is: {0}", Console.WriteLine("Double PI is: {0}", doublePI);doublePI);
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Abnormalities in the Abnormalities in the Floating-Point Floating-Point
CalculationsCalculations Sometimes abnormalities can be Sometimes abnormalities can be
observed when using floating-point observed when using floating-point numbersnumbers Comparing floating-point numbers Comparing floating-point numbers
can not be performed directly with can not be performed directly with the the ==== operator operator
Example:Example:double a = 1.0f;double a = 1.0f;double b = 0.33f;double b = 0.33f;double sum = 1.33f;double sum = 1.33f;bool equal = (a+b == sum); // False!!!bool equal = (a+b == sum); // False!!!Console.WriteLine("a+b={0} sum={1} Console.WriteLine("a+b={0} sum={1} equal={2}",equal={2}", a+b, sum, equal);a+b, sum, equal); 17
Decimal Floating-Point Decimal Floating-Point TypesTypes
There is a special decimal floating-There is a special decimal floating-pointpoint real number type in C#: real number type in C#: decimaldecimal (±1,0 × 10(±1,0 × 10-28-28 to ±7,9 × 10 to ±7,9 × 102828): ):
128-bits, precision of 28-29 digits128-bits, precision of 28-29 digits
Used for financial calculationsUsed for financial calculations
No round-off errorsNo round-off errors
Almost no loss of precisionAlmost no loss of precision The default value of The default value of decimaldecimal type is:type is:
0.00.0MM ( (MM is the suffix for decimal is the suffix for decimal numbers)numbers)
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Floating-Point and Floating-Point and Decimal Floating-Decimal Floating-
Point TypesPoint TypesLive DemoLive Demo
Boolean TypeBoolean Type
The Boolean Data TypeThe Boolean Data Type The The Boolean data typeBoolean data type::
Is declared by the Is declared by the boolbool keyword keyword
Has two possible values: Has two possible values: truetrue and and falsefalse
Is useful in logical expressionsIs useful in logical expressions The default value is The default value is falsefalse
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Boolean Values – Boolean Values – ExampleExample
Example of boolean variables Example of boolean variables taking values of taking values of truetrue or or falsefalse::
int a = 1;int a = 1;int b = 2;int b = 2;
bool greaterAB = (a > b);bool greaterAB = (a > b);
Console.WriteLine(greaterAB); // FalseConsole.WriteLine(greaterAB); // False
bool equalA1 = (a == 1);bool equalA1 = (a == 1);
Console.WriteLine(equalA1); // TrueConsole.WriteLine(equalA1); // True
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Boolean TypeBoolean TypeLive DemoLive Demo
Character TypeCharacter Type
The Character Data The Character Data TypeType
The The character data typecharacter data type:: Represents symbolic informationRepresents symbolic information
Is declared by the Is declared by the charchar keyword keyword
Gives each symbol a corresponding Gives each symbol a corresponding integer codeinteger code
Has a Has a '\0''\0' default value default value
Takes 16 bits of memory (from Takes 16 bits of memory (from U+0000U+0000 to to U+FFFFU+FFFF))
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Characters and CodesCharacters and Codes The example below shows that The example below shows that
every symbol has an its unique every symbol has an its unique Unicode code:Unicode code:char symbol = 'a';char symbol = 'a';Console.WriteLine("The code of '{0}' is: Console.WriteLine("The code of '{0}' is: {1}",{1}", symbol, (int) symbol);symbol, (int) symbol);
symbol = 'b';symbol = 'b';Console.WriteLine("The code of '{0}' is: Console.WriteLine("The code of '{0}' is: {1}",{1}", symbol, (int) symbol);symbol, (int) symbol);
symbol = 'A';symbol = 'A';Console.WriteLine("The code of '{0}' is: Console.WriteLine("The code of '{0}' is: {1}",{1}", symbol, (int) symbol);symbol, (int) symbol);
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Character TypeCharacter TypeLive DemoLive Demo
String TypeString Type
The String Data TypeThe String Data Type The The string data typestring data type::
Represents a sequence of Represents a sequence of characterscharacters
Is declared by the Is declared by the stringstring keyword keyword
Has a default value Has a default value nullnull (no value) (no value)
Strings are enclosed in quotes:Strings are enclosed in quotes:
Strings can be concatenatedStrings can be concatenated Using the Using the ++ operator operator
string s = "Microsoft .NET Framework";string s = "Microsoft .NET Framework";
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Saying Hello – ExampleSaying Hello – Example Concatenating the two names of a Concatenating the two names of a
person to obtain his full name:person to obtain his full name:
NOTE: a space is missing between NOTE: a space is missing between the two names! We have to add it the two names! We have to add it manuallymanually
string firstName = "Ivan";string firstName = "Ivan";string lastName = "Ivanov";string lastName = "Ivanov";Console.WriteLine("Hello, {0}!\n", Console.WriteLine("Hello, {0}!\n", firstName);firstName);
string fullName = firstName + " " + string fullName = firstName + " " + lastName;lastName;Console.WriteLine("Your full name is {0}.",Console.WriteLine("Your full name is {0}.", fullName);fullName);
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String TypeString TypeLive DemoLive Demo
Object TypeObject Type
The Object TypeThe Object Type The object type:The object type:
Is declared by the Is declared by the objectobject keyword keyword
Is the base type of all other typesIs the base type of all other types
Can hold values of any typeCan hold values of any type
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Using ObjectsUsing Objects Example of an object variable Example of an object variable
taking different types of data:taking different types of data:
object dataContainer = 5;object dataContainer = 5;Console.Write("The value of dataContainer is: Console.Write("The value of dataContainer is: ");");Console.WriteLine(dataContainer);Console.WriteLine(dataContainer);
dataContainer = "Five";dataContainer = "Five";Console.Write("The value of dataContainer is: Console.Write("The value of dataContainer is: ");");Console.WriteLine(dataContainer);Console.WriteLine(dataContainer);
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ObjectsObjectsLive DemoLive Demo
Introducing Introducing VariablesVariables
pp qqii
What Is a Variable?What Is a Variable? A variable is a:A variable is a:
Placeholder of information that can Placeholder of information that can usually be changed at run-timeusually be changed at run-time
Variables allow you to:Variables allow you to: Store informationStore information
Retrieve the stored informationRetrieve the stored information
Manipulate the stored informationManipulate the stored information
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Variable CharacteristicsVariable Characteristics A variable has:A variable has:
NameName Type (of stored data)Type (of stored data) ValueValue
Example:Example:
Name: Name: countercounter Type: Type: intint Value: Value: 55
int counter = 5;int counter = 5;
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Declaring And Declaring And Using VariablesUsing Variables
Declaring VariablesDeclaring Variables When declaring a variable we:When declaring a variable we:
Specify its typeSpecify its type
Specify its name (called identifier)Specify its name (called identifier)
May give it an initial valueMay give it an initial value
The syntax is the following:The syntax is the following:
Example:Example:
<data_type> <identifier> [= <initialization>];<data_type> <identifier> [= <initialization>];
int height = 200;int height = 200;
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IdentifiersIdentifiers Identifiers may consist of:Identifiers may consist of:
Letters (Unicode) Letters (Unicode)
Digits [0-9]Digits [0-9]
Underscore "_"Underscore "_" IdentifiersIdentifiers
Can begin only with a letter or an Can begin only with a letter or an underscoreunderscore
Cannot be a C# keywordCannot be a C# keyword
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Identifiers (2)Identifiers (2) IdentifiersIdentifiers
Should have a descriptive nameShould have a descriptive name
It is recommended to use only Latin It is recommended to use only Latin lettersletters
Should be neither too long nor too Should be neither too long nor too shortshort
Note:Note: In C# small letters are considered In C# small letters are considered
different than the capital letters different than the capital letters (case sensitivity)(case sensitivity)
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Identifiers – ExamplesIdentifiers – Examples Examples of correct identifiers:Examples of correct identifiers:
Examples of incorrect identifiers:Examples of incorrect identifiers:int new;int new; // new is a keyword// new is a keywordint 2Pac;int 2Pac; // Cannot begin with a digit// Cannot begin with a digit
int New = 2; // Here N is capitalint New = 2; // Here N is capitalint _2Pac; // This identifiers begins with _int _2Pac; // This identifiers begins with _
string поздрав = "Hello"; // Unicode symbols usedstring поздрав = "Hello"; // Unicode symbols used// The following is more appropriate:// The following is more appropriate:string greeting = "Hello"; string greeting = "Hello";
int n = 100; // Undescriptiveint n = 100; // Undescriptiveint numberOfClients = 100; // Descriptiveint numberOfClients = 100; // Descriptive
// Overdescriptive identifier:// Overdescriptive identifier:int numberOfPrivateClientOfTheFirm = 100;int numberOfPrivateClientOfTheFirm = 100;
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Assigning Assigning Values To Values To VariablesVariables
Assigning ValuesAssigning Values Assigning of values to variablesAssigning of values to variables
Is achieved by the Is achieved by the == operator operator The The == operator has operator has
Variable identifier on the leftVariable identifier on the left
Value of the corresponding data Value of the corresponding data type on the righttype on the right
Could be used in a cascade calling, Could be used in a cascade calling, where assigning is done from right where assigning is done from right to leftto left
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Assigning Values – Assigning Values – ExamplesExamples
Assigning values example:Assigning values example:
int firstValue = 5;int firstValue = 5;int secondValue;int secondValue;int thirdValue;int thirdValue;
// Using an already declared variable:// Using an already declared variable:secondValue = firstValue;secondValue = firstValue;
// The following cascade calling assigns// The following cascade calling assigns// 3 to firstValue and then firstValue// 3 to firstValue and then firstValue// to thirdValue, so both variables have// to thirdValue, so both variables have// the value 3 as a result:// the value 3 as a result:
thirdValue = firstValue = 3; // Avoid this!thirdValue = firstValue = 3; // Avoid this!
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Initializing VariablesInitializing Variables InitializingInitializing
Is assigning of initial valueIs assigning of initial value
Must be done before the variable is Must be done before the variable is used!used!
Several ways of initializing:Several ways of initializing:
By using the By using the newnew keyword keyword
By using a literal expressionBy using a literal expression
By referring to an already initialized By referring to an already initialized variablevariable 47
Initialization – Initialization – ExamplesExamples
Example of some initializations:Example of some initializations:
// The following would assign the default// The following would assign the default// value of the int type to num:// value of the int type to num:int num = new int(); // num = 0int num = new int(); // num = 0
// This is how we use a literal expression:// This is how we use a literal expression:float heightInMeters = 1.74f;float heightInMeters = 1.74f;
// Here we use an already initialized // Here we use an already initialized variable:variable:string greeting = "Hello World!";string greeting = "Hello World!";string message = greeting;string message = greeting;
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Assigning and Assigning and Initializing Initializing VariablesVariables
Live DemoLive Demo
LiteralsLiterals
What are Literals?What are Literals? Literals are:Literals are:
Representations of values in the Representations of values in the source codesource code
There are six types of literalsThere are six types of literals BooleanBoolean IntegerInteger RealReal CharacterCharacter StringString The The nullnull literal literal 51
Boolean and Integer Boolean and Integer LiteralsLiterals
The boolean literals are:The boolean literals are: truetrue falsefalse
The integer literals:The integer literals: Are used for variables of type Are used for variables of type intint, , uintuint, , longlong, and , and ulongulong
Consist of digitsConsist of digits May have a sign (May have a sign (++,,--)) May be in a hexadecimal formatMay be in a hexadecimal format
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Integer LiteralsInteger Literals Examples of integer literalsExamples of integer literals
The The ''0x0x'' and and ''0X0X'' prefixes mean a prefixes mean a hexadecimal value, e.g. hexadecimal value, e.g. 0xA8F10xA8F1
The The ''uu'' and and ''UU'' suffixes mean a suffixes mean a ulongulong or or uintuint type, e.g. type, e.g. 12345678U12345678U
The The ''ll'' and and ''LL'' suffixes mean a suffixes mean a longlong or or ulongulong type, e.g. type, e.g. 9876543L9876543L
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Integer Literals – Integer Literals – ExampleExample
Note: the letter ‘Note: the letter ‘ll’ is easily confused with ’ is easily confused with the digit ‘the digit ‘11’ so it’s better to use ‘’ so it’s better to use ‘LL’!!!’!!!
// The following variables are// The following variables are// initialized with the same value:// initialized with the same value:int numberInHex = -0x10;int numberInHex = -0x10;int numberInDec = -16;int numberInDec = -16;
// The following causes an error,// The following causes an error,because 234u is of type uintbecause 234u is of type uintint unsignedInt = 234u;int unsignedInt = 234u;
// The following causes an error,// The following causes an error,because 234L is of type longbecause 234L is of type longint longInt = 234L;int longInt = 234L;
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Real LiteralsReal Literals The real literals:The real literals:
Are used for values of type Are used for values of type floatfloat, , doubledouble and and decimaldecimal
May consist of digits, a sign and “May consist of digits, a sign and “..””
May be in exponential notation: May be in exponential notation: 6.02e+236.02e+23
The “The “ff” and “” and “FF” suffixes mean ” suffixes mean floatfloat The “The “dd” and “” and “DD” suffixes mean ” suffixes mean doubledouble The “The “mm” and “” and “MM” suffixes mean ” suffixes mean decimaldecimal The default interpretation is The default interpretation is doubledouble
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Real Literals – ExampleReal Literals – Example Example of incorrect Example of incorrect floatfloat literal: literal:
A correct way to assign floating-A correct way to assign floating-point value (using also the point value (using also the exponential format):exponential format):
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// The following causes an error// The following causes an error// because 12.5 is double by default// because 12.5 is double by defaultfloat realNumber = 12.5;float realNumber = 12.5;
// The following is the correct// The following is the correct// way of assigning the value:// way of assigning the value:float realNumber = 12.5f;float realNumber = 12.5f;
// This is the same value in exponential format:// This is the same value in exponential format:realNumber = 1.25e+7f;realNumber = 1.25e+7f;
Character LiteralsCharacter Literals The character literals:The character literals:
Are used for values of the Are used for values of the charchar typetype
Consist of two single quotes Consist of two single quotes surrounding the character value: surrounding the character value: ''<value><value>''
The value may be:The value may be: SymbolSymbol
The code of the symbolThe code of the symbol
Escaping sequenceEscaping sequence57
Escaping SequencesEscaping Sequences Escaping sequences are:Escaping sequences are:
Means of presenting a symbol that is Means of presenting a symbol that is usually interpreted otherwise (like usually interpreted otherwise (like ''))
Means of presenting system symbols Means of presenting system symbols (like the new line symbol)(like the new line symbol)
Common escaping sequences are:Common escaping sequences are: \'\' for single quote for single quote \"\" for double quote for double quote
\\\\ for backslash for backslash \n\n for new linefor new line
\uXXXX\uXXXX for denoting any other Unicode for denoting any other Unicode symbolsymbol
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Character Literals – Character Literals – ExampleExample
Examples of different character Examples of different character literals:literals:char symbol = 'a'; // An ordinary symbolchar symbol = 'a'; // An ordinary symbol
symbol = '\u006F'; // Unicode symbol code in symbol = '\u006F'; // Unicode symbol code in // a hexadecimal format // a hexadecimal format
symbol = '\u8449'; // symbol = '\u8449'; // 葉 葉 ((Leaf in Traditional Leaf in Traditional Chinese)Chinese)
symbol = '\''; // Assigning the single quote symbol = '\''; // Assigning the single quote symbolsymbol
symbol = '\\'; // Assigning the backslash symbolsymbol = '\\'; // Assigning the backslash symbol
symbol = '\n'; // Assigning new line symbolsymbol = '\n'; // Assigning new line symbol
symbol = '\t'; // Assigning TAB symbolsymbol = '\t'; // Assigning TAB symbol
symbol = "a"; // Incorrect: use single quotessymbol = "a"; // Incorrect: use single quotes 59
String LiteralsString Literals String literals:String literals:
Are used for values of the string Are used for values of the string typetype
Consist of two double quotes Consist of two double quotes surrounding the value: surrounding the value: ""<value><value>""
May have a May have a @@ prefix which ignores prefix which ignores the used escaping sequences: the used escaping sequences: @@"<value>""<value>"
The value is a sequence of The value is a sequence of character literalscharacter literals
string s = "I am a sting literal";string s = "I am a sting literal";
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String Literals – String Literals – ExampleExample
Benefits of quoted strings (the Benefits of quoted strings (the @@ prefix):prefix):
In quoted strings In quoted strings \"\" is used instead is used instead of of """"!!
// Here is a string literal using escape sequences// Here is a string literal using escape sequencesstring quotation = "\"Hello, Jude\", he said.";string quotation = "\"Hello, Jude\", he said.";string path = "C:\\WINNT\\Darts\\Darts.exe";string path = "C:\\WINNT\\Darts\\Darts.exe";
// Here is an example of the usage of @// Here is an example of the usage of @quotation = @"""Hello, Jimmy!"", she answered.";quotation = @"""Hello, Jimmy!"", she answered.";path = @"C:\WINNT\Darts\Darts.exe";path = @"C:\WINNT\Darts\Darts.exe";
string str = @"somestring str = @"sometext";text";
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String LiteralsString LiteralsLive DemoLive Demo
Nullable TypesNullable Types
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Nullable TypesNullable Types NullableNullable types are instances of the types are instances of the System.NullableSystem.Nullable structstruct Wrapper over the Wrapper over the primitiveprimitive typestypes
E.g. E.g. int?int?, , double?double?, etc., etc. NullabeNullabe type can represent the type can represent the
normal range of values for its normal range of values for its underlying value type, plus an underlying value type, plus an additional additional nullnull value value
Useful when dealing with Useful when dealing with DatabasesDatabases or other structures that have default or other structures that have default value value nullnull
Nullable Types – Nullable Types – ExampleExample
int? someInteger = null;int? someInteger = null;Console.WriteLine(Console.WriteLine( "This is the integer with Null value -> " + "This is the integer with Null value -> " + someInteger);someInteger);someInteger = 5;someInteger = 5;Console.WriteLine(Console.WriteLine( "This is the integer with value 5 -> " + "This is the integer with value 5 -> " + someInteger);someInteger);
double? someDouble = null;double? someDouble = null;Console.WriteLine(Console.WriteLine( "This is the real number with Null value -> " "This is the real number with Null value -> " + someDouble);+ someDouble);someDouble = 2.5;someDouble = 2.5;Console.WriteLine(Console.WriteLine( "This is the real number with value 5 -> " + "This is the real number with value 5 -> " + someDouble);someDouble);
Example with Example with IntegerInteger::
Example with Example with DoubleDouble::
Nullable TypesNullable TypesLive DemoLive Demo
66
QuestionsQuestions??
Primitive Data Primitive Data Types and Types and VariablesVariables
http://academy.telerik.com
ExercisesExercises
1.1. Declare five variables choosing for each of Declare five variables choosing for each of them the most appropriate of the types them the most appropriate of the types bytebyte, , sbytesbyte, , shortshort, , ushortushort, , intint, , uintuint, , longlong, , ulongulong to to represent the following values: 52130, -115, represent the following values: 52130, -115, 4825932, 97, -10000.4825932, 97, -10000.
2.2. Which of the following values can be assigned Which of the following values can be assigned to a variable of type to a variable of type floatfloat and which to a and which to a variable of type variable of type doubledouble: 34.567839023, 12.345, : 34.567839023, 12.345, 8923.1234857, 3456.091?8923.1234857, 3456.091?
3.3. Write a program that safely compares floating-Write a program that safely compares floating-point numbers with precision of point numbers with precision of 0.0000010.000001..
68
Exercises (2)Exercises (2)
4.4. Declare an integer variable and assign it Declare an integer variable and assign it with the value 254 in hexadecimal format. with the value 254 in hexadecimal format. Use Windows Calculator to find its Use Windows Calculator to find its hexadecimal representation.hexadecimal representation.
5.5. Declare a character variable and assign it Declare a character variable and assign it with the symbol that has Unicode code 72. with the symbol that has Unicode code 72. Hint: first use the Windows Calculator to Hint: first use the Windows Calculator to find the hexadecimal representation of 72.find the hexadecimal representation of 72.
6.6. Declare a boolean variable called Declare a boolean variable called isFemaleisFemale and assign an appropriate value and assign an appropriate value corresponding to your gender.corresponding to your gender.
69
Exercises (3)Exercises (3)7.7. Declare two Declare two stringstring variables and assign variables and assign
them with “Hello” and “World”. Declare an them with “Hello” and “World”. Declare an objectobject variable and assign it with the variable and assign it with the concatenation of the first two variables concatenation of the first two variables (mind adding an interval). Declare a third (mind adding an interval). Declare a third stringstring variable and initialize it with the variable and initialize it with the value of the object variable (you should value of the object variable (you should perform type casting).perform type casting).
8.8. Declare two Declare two stringstring variables and assign variables and assign them with following value:them with following value:
Do the above in two different ways: with and Do the above in two different ways: with and without using quoted strings.without using quoted strings.
The "use" of quotations causes difficulties. The "use" of quotations causes difficulties.
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Exercises (4)Exercises (4)9.9. Write a program thatWrite a program that prints an isosceles prints an isosceles
triangle of 9 copyright symbols triangle of 9 copyright symbols ©©. Use . Use Windows Character Map to find the Unicode Windows Character Map to find the Unicode code of the code of the ©© symbol. symbol.
10.10. A marketing firm wants to keep record of its A marketing firm wants to keep record of its employees. Each record would have the employees. Each record would have the following characteristics – first name, family following characteristics – first name, family name,name, age,age, gender (m or f), ID number,gender (m or f), ID number, unique employee number (27560000 to unique employee number (27560000 to 27569999). Declare the variables needed to 27569999). Declare the variables needed to keep the information for a single employee keep the information for a single employee using appropriate data typesusing appropriate data types andand descriptive descriptive names.names.
11.11. Declare two integer variables and assign Declare two integer variables and assign them with 5 and 10 and after that exchange them with 5 and 10 and after that exchange their values.their values. 71