Bài giảng lập trình c 2010 chương 6 đh đồng nai công nghệ đồng nai

DONG NAI UNIVERSITY OF TECHNOLOGYString Properties specified character position in the current String object.. DONG NAI UNIVERSITY OF TECHNOLOGYString Methods Name public bool Contains s

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Represents text as a series

of Unicode characters.

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Constructor

There are many overload Constructors I would like to tell you the Constructor below:

String Constructor ( Char [])

class to the value indicated by an array

of Unicode characters

(new char[]{'H','U','I'});

MessageBox.Show(strHUI);

String strHUI = new String

MessageBox.Show(strHUI);

Use string or String ?

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“a”==“A”?false

“a”==“a”?true

Determines whether two specified strings have the same value

Inequality(!=)

“a”!=“A”?true

“a”!=“a”?false

Determines whether two specified strings have different values

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String Properties

specified character position

in the current String object

characters in the current String object

( string strA, string strB )Description

and returns an integer that indicates

their relative position in the sort order

0 strA equals strB

-1 strA is less than strB

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string strA, string strB,

bool ignoreCase )

Description

,ignoring or honoring their case, and

returns an integer that indicates their

relative position in the sort order

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String Methods

Example

(“A", “a”,true);nRet=0

(“a", “A”,false);nRet=-1

(“A", “a”,false);nRet=1

Compares this instance with a

whether this instance precedes,

follows, or appears in the same

position in the sort order as the

specified String (0 ; 1 ; -1)

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string str = string.Copy("Teo");

string str1 = "Ti";

string str2 =string.Copy(str1);

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String Methods

Name

public bool Contains( string value )

Description

Returns a value indicating whether the

this string

Return true or false

string strA = "Trần Văn Tèo";

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String Methods

Name

public bool EndsWith( string value )

Description

Determines whether the end of this

string instance matches the specified

string

Return true or false

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Determines whether the end of this

string instance matches the specified

string when compared using the

specified comparison option

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String Methods

Name

public static string Format

(string format, params Object[] args )

Description

Replaces the format item in a

specified string with the string

representation of a corresponding

object in a specified array

strFormat = string.Format("Tỉ giá {0:d}

= {1:c}", DateTime.Today, 22.3);

MessageBox.Show(strFormat);

HO CHI MINH UNIVERSITY OF INDUSTRY

Author: Duy Thanh Tran – Phone : 0987773061 - Email: thanhxeiko@gmail.com – Blog: http://thanhxeiko.wordpress.com

occurrence of the specified Unicode

character in this string

of value if that character is found, or -1

if it is not

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occurrence of the specified string in

this instance

The zero-based index position

of value if that string is found, or -1 if it

is not If value is String.Empty, the

return value is 0

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String Methods

Example

string str = "Học! Học Nữa ! Học Mãi" ;

int nRet = str.IndexOf( "Học" );

StringComparison comparisonType)

Description

Reports the index of the first

occurrence of the specified string in

the current String object A parameter

specifies the type of search to use for

the specified string

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String Methods

Example

string strHUI = "Welcome C# 2010" ;

int nRet = strHUI.IndexOf( "WELCOME" ,

Reports the index of the first

occurrence in this instance of any

character in a specified array of

Unicode characters

The zero-based index position where

any character in anyOf was found; -1 if

no character in anyOf was found

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String Methods

Example

string str = "Không! không; có? có?" ;

int nRet=str.IndexOfAny( new char [] { '>' , '?' , ';' });

 nRet=12

string value )Description

of String at a specified index position

in this instance

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Reports the index position of the last

occurrence of a specified Unicode

character within this instance

The zero-based index position

of value if that character is found, or -1

if it is not

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Reports the index position of the last

occurrence of a specified string within

this instance

The zero-based index position of value if that

string is found, or -1 if it is not

If value is String.Empty , the return value is the

last index position in this instance

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String Methods

Example

string str = "Học ! Học Nữa ! Học Mãi";

int nRet = str.LastIndexOf("Học");

nRet =16

nRet = str.LastIndexOf("HỌC");

StringComparison comparisonType )

Description

Reports the index of the last

occurrence of a specified string within

the current String object A parameter

specifies the type of search to use for

the specified string

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String Methods

Example

string str = "Học ! Học Nữa ! Học Mãi" ;

int nRet = str.LastIndexOf( "HỌC" ,

StringComparison OrdinalIgnoreCase);

 nRet =16

Deletes all the characters from this

string beginning at a specified position

and continuing through the last

position

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int count )Description

Deletes a specified number of

beginning at a specified position

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char newChar )Description

Returns a new string in which all

occurrences of a specified Unicode

character in this instance are replaced

character

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string newValue )Description

Returns a new string in which all

occurrences of a specified string in the

current instance are replaced with

another specified string

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String Methods

Example

string str = "Phải xem tài liệu trước khi tới lớp, tài liệu

này rất quan trọng!" ;

str = str.Replace( "tài liệu" , "document" );

 str = "Phải xem document trước khi tới lớp,

document này rất quan trọng!" ;

separator )

Description

Returns a string array that contains

the substrings in this instance that are

delimited by elements of a specified

Unicode character array

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String Methods

Example

string str = "Trần văn tèo;21 tuổi;Chưa

vợ;Côn Đảo";

string []strArr=str.Split(new char[]{';'});

foreach (string s in strArr)

StringSplitOptions options )

Description

Returns a string array that contains

the substrings in this string that are

delimited by elements of a specified

string array A parameter specifies

whether to return empty array

elements

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String Methods

Example

string str = "Trần văn tèo;;21 tuổi;Chưa vợ;Côn Đảo" ;

string []strArr=str.Split( new string [] { ";" },

string str = "Trần văn tèo;;21 tuổi;Chưa vợ;Côn Đảo" ;

string []strArr=str.Split( new string [] { ";" },

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String Methods

Name

public bool StartsWith( string value )

Description

Determines whether the beginning of

this string instance matches the

specified string

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Determines whether the beginning of

this string instance matches the

specified string when compared using

the specified comparison option

công</head>" ;

bool bStart=str.StartsWith( "<HEAD>" ,

StringComparison Ordinal);

MessageBox Show(bStart.ToString());False

bool bStart=str.StartsWith( "<HEAD>" ,

StringComparison OrdinalIgnoreCase);

True

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String Methods

Name

public string Substring( int startIndex )

Description

Retrieves a substring from this

instance The substring starts at a

specified character position

string strSub = str.Substring(5);

MessageBox Show(strSub);

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Retrieves a substring from this

instance The substring starts at a

specified character position and has a

specified length

string strSub = str.Substring(10,13);

MessageBox Show(strSub);

strSub = str.Substring(0,9);

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String Methods

Name

public char[] ToCharArray()

Description

Copies the characters in this instance

to a Unicode character array

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MessageBox Show(str);

 microsoft visual studio 2010

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MessageBox Show(str);

MICROSOFT VISUAL STUDIO 2010

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String Methods

Name

public string Trim()

Description

Removes all leading and trailing

current String object

MessageBox Show(str.Length+ "" ); //35

MessageBox Show(str);

 " Microsoft Visual Studio 2010 "

string str = " Microsoft Visual Studio 2010 " ;

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Removes all trailing occurrences of a

set of characters specified in an array

str=str.TrimEnd(new char [] { ' ' , '?' , '!' , '#' });

MessageBox Show(str.Length+ "" );// 28

MessageBox Show(str);

 "Microsoft Visual Studio 2010"

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Removes all leading occurrences of a

set of characters specified in an array

str=str.TrimStart(new char [] { ' ' , '?' , '!' , '#' });

MessageBox Show(str.Length+ "" );// 28

MessageBox Show(str);

 "Microsoft Visual Studio 2010"

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DEMO String & Dictionary

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