In-Built Functions. String Handling Functions:-

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1 L i b r a r y F u n c t i o n s : String Handling Functions:- In-Built Functions 1) LTrim() :- Usage: The LTrim() function returns a string containing a copy of specified string without leading spaces. Syntax: LTrim(String) Example: Private Sub Form1_Click() Debug.Print (LTrim( Cojit College )) Returns Cojit College 2) RTrim(): - Usage: The RTrim() function returns a string containing a copy of specified string without trailing spaces. Syntax: RTrim(String) Example: Private Sub Form1_Click() Debug.Print (RTrim( Cojit College )) Returns Cojit College 3) Trim():- Usage: The Trim() function returns a string containing a copy of specified string without both leading and trailing spaces. Syntax: Trim(String) Example: Private Sub Form1_Click() Debug.Print (Trim( Cojit College )) Returns Cojit College 4) Mid():- Usage:- It returns a string containing a specified number of characters from a string. Syntax:- Mid(String,Start,[Length]) Parts of the Syntax: String-It is string expression from which characters are returned. Start-It is character position in string at which the part to be taken begins. If start is greater than the number of characters in string Mid() returns a zero-length string( ) Length-It is number of characters to return. If omitted or if there are fewer than length characters in the text, all characters from the start position to the end of the string are returned. Private Sub Form1_Click() Const st As String= Cojit College Debug.Print (Mid(st,1,5)) Returns Cojit Prepared By: Ankit Shah Page 1

2 Debug.Print (Mid(st,9,7)) Returns llege Debug.Print (Mid(st,1)) Returns Cojit College (starts from 1 and all string print) Debug.Print (Mid(st,9)) Returns llege Debug.Print (Mid(st,16)) Returns 5) Len():- Usage:- It returns the number of characters in a string or the number of bytes required to store a variable. Syntax:- Len(String Variable) Parts of the Syntax:- String-It is any valid string expression, if string contains zero length, the function returns empty. Variable-It is any valid variable name. If variable name is variant, Len() treats it the same as a string and always returns the number of characters it contains. For example:- Private Sub Form1_Click() Dim a As Integer, b As String, c a=1234 Debug.Print (Len(a)) 2 (Bytes) Debug.Print (Len(b)) 0 (Total Characters) Debug.Print (Len(c)) 0 b= Cojit College Debug.Print (Len(b)) 13 (Total Characters) 6) InStr():- Usage:- It returns the location of the first occurrence of one string within another. Syntax:-Instr(String1,String2[,Compare]) Parts of the Syntax:- Start-It is numeric expression that sets the stating position for each search. If it is omitted, search begins at the first character position. Here stat argument is required if compare is specified. String1- It is string which you want to find from string1 String2-It is string from which you want to find. Compare-It specifies the type of comparison. If it s omitted it will set either default compare method i.e. binary comparison or according to the option compare setting. Compare argument settings are: Constant Value Description vbbinarycompare 0 It performs a binary comparison i.e. case sensitive matching. vbtextcompare 1 It performs a textual comparison i.e. case insensitive matching. vbdatabasecompare 2 It can only be used within Microsoft Access. It performs a comparison based on information in your database. Prepared By: Ankit Shah Page 2

3 Return Values are: If InStr() returns 1) String1 is zero length 0 2) String2 is zero length 1 3) String2 is not found 0 4) String1is found within String2 Position at which match is found 5) Start > String2 0 For Example: Option Compare Text Dim str1, str2 As String str1= Cojit College str2= School Debug.Print (Instr(1,,str2)) Returns 0 Debug.Print (Instr(1,str1, )) Returns 1 Debug.Print (Instr(1,str1,str2)) Returns 0 str2= College Debug.Print (Instr(str1,str2)) Returns 7 Debug.Print (Instr(1,str1,str2,vbBinaryCompare)) Returns 7 7) StrComp():- Usage:- It returns an integer indicating the result of a string comparison. Syntax:-StrComp(String1, String2 [,Compare]) Parts of Syntax: String1 & String2 Any valid string expression. Compare It specifies the type of comparison i.e. Binary, Text or Database comparison. (See InStr() for more information) Return Values are: If StrComp() returns String1<String2-1 String1=String2 0 String1>String2 1 For Example:- Debug.Print (StrComp("ABCD", "ABCDD")) 'Returns -1 Debug. Print (StrComp("ABCD", "ABCD")) 'Returns 0 Debug.Print (StrComp("ABCDD", "ABCD")) 'Returns 1 Debug.Print (StrComp("abcd", "Abcd", vbbinarycompare)) 'Returns 1 Debug.Print (StrComp("Abcd", "Abcd", vbtextcompare)) 'Returns 0 Prepared By: Ankit Shah Page 3

4 8) StrReverse() Usage:-It returns a string in which the character order of a specified string is reversed. Syntax: StrReverse(String) For Example:- Debug.Print (StrReverse( College )) Returns egelloc 9) StrConv() Usage:-StrConv() convers the give string value into specified conversion format Syntax:-StrConv(String1,Conversion[,LCID]) Parts of the Syntax: String Any valid string expression Conversion It specifies the type of conversion. LCID It is Local ID of your system. If it is omitted the system Local ID will be default ID. The Conversion arguments are: - Remarks: - * vbwide and vbnarrow applied to Far East locales. ** vbkatakana and vbhiragana applied to Japan only. For Example:- Debug.Print(StrConv("Cojit", VbStrConv.Lowercase)) 'Returns cojit Debug.Print(StrConv("cojit college", VbStrConv.ProperCase)) ' Cojit College 10) Space():- Usage: -Space() function returns a string consisting of the specified number of space. It is useful for to format output. Syntax:- Space(number) The required number argument is the number of spaces you want in the string. For Debug.Print(Space(10)) Debug.Print("Name") Debug.Print(Space(10)) Debug.Print("Address") 11) UCase():- Usage:-UCase() function returns a string that has been converted to uppercase. Syntax: - UCase(StringExp) Remarks:- Only upper letter are converted to lowercase, all lower letters and non-letters characters remain unchanged. Prepared By: Ankit Shah Page 4

5 For Example:- Debug.Print (UCase("college")) 'Returns COLLEGE 12) LCase():- Usage:-LCase() function returns a string that has been converted to uppercase. Syntax: - LCase(StringExp) Remarks:- Only upper letter are converted to lowercase, all lower letters and non-letters characters remain unchanged. For Example:- Debug.Print (LCase( COLLEGE )) Returns college Conversion Functions:- 1) Hex():- Usage:-It returns a string representing the hexadecimal value of a number. Syntax:- Hex(Numeric_Exp) Example: Debug.Print (Hex(5)) Returns 5 Debug.Print (Hex(10)) Returns A 2) Oct(): - Usage:- It returns a string representing the octal value of a number Syntax: - Oct(Numeric_Exp) Example:- Private Sub From_Click() Debug.Print (Oct(12)) Returns 14 3) Str(): - Usage:- It returns a string representing the conversion of a number into a string. It inserts a leading space for positive or unsigned numbers to act as a placeholder for the sign. Syntax:- Str(Numeric_Exp) Example: Debug.Print (Str(45)) Returns 45 Prepared By: Ankit Shah Page 5

6 4) CInt():- Usage:- It returns the integer portion of any give numeric expression rounding the fractional part of a number. CInt function always rounds it to the nearest number. For example, 0.5 rounds to 0, and 1.5 rounds to 2. Syntax:- CInt(Numeric_Exp) Example:- Debug.Print (CInt(1.9)) 'Returns 2 Debug.Print (CInt(-1.9)) 'Returns 2 Debug.Print (CInt(-1.2)) 'Returns 1 5) CBool(): Usage:- It returns Boolean or logical value representing True or False corresponding to the given expression. Syntax:- CBool(Logical_Exp) Example:- Debug.Print CBool(10 < 20) 'Returns True 6) CLng():- Usage:- It converts any give numeric expressing into Long data type. Syntax:- CLng(Numeric_Exp) Example:- Debug.Print (CLng(13.24)) 'Returns 13 Debug.Print (CLng(13.54)) 'Returns 14 7) CDbl():- Usage:- it converts any given numeric expression into Double data type. Syntax:- CDbl(Numeric_Exp) Example: Debug.Print (CDbl(1 / 7)) 'Returns ) CSng():- Usage:-It converts any given numeric expression into Single data type. Syntax:- CSng(Numeric_Exp) Example:- Debug.Print (CSng(1 / 7)) 'Returns Prepared By: Ankit Shah Page 6

7 9) Cbyte():- Usage:- It converts any given numeric expression into Byte data type. Syntax:- Cbyte(Numeric_Exp) Example:- Debug.Print (CByte(500 / 3)) 'Returns 167 Debug.Print (CByte(5000 / 3)) 10) Cdec(): Usage: - It converts any numeric expression into Decimal data type with the length of 28 decimal numbers. Syntax:- Cdec(Numeric_Exp) Debug.Print (CDec(1 / 49)) 'Returns Debug.Print (CDbl(1 / 49)) 'Returns E-02 Debug.Print (CDec(1E-28)) 'Returns Debug.Print (CDbl(1E-28)) 'Returns 1E-28 11) Chr(): - Usage: - It returns a string containing the character associated with the specified character code. Numbers from 0 31 are the same as standard, nonprintable ASCII codes. For example, Chr(10) returns a linefeed character. The normal range for charcode is Syntax: - Chr(Numeric_Exp) Debug.Print (Chr(65)) ' Returns A Debug.Print (Chr(97)) ' Returns a Debug.Print (Chr(62)) ' Returns > Debug.Print (Chr(37)) ' Returns % 12) Asc(): - Usage: - It returns an integer between representing the character code corresponding to the first letter in a string. Syntax:- Asc(Character_Exp) Debug.Print (Asc("A")) ' Returns 65. Debug.Print (Asc("a")) ' Returns 97. Debug.Print (Asc("Apple )) ' Returns 65. Prepared By: Ankit Shah Page 7

8 13) Val(): - Usage:- It returns the given string value to double value. Syntax:- Val(String) Example:- Text3.Text= Val(Text1.Text) + Val(Text2.Text) Mathematical Functions [Imports System.Math] 1) Abs (): - Usage: - It returns the absolute value of the given numeric expression removing the plus or minus sign. If argument contains Null, Null is returned; if it is an un-initialized variable, zero is returned. Syntax: - Abs(Numeric_Exp) Debug.Print(Math.Abs(1.6)) 'Returns 1.6 Debug.Print(Math.Abs(-1.6)) 'Returns 1.6 2) Atan (): - Usage: - It returns a Double specifying the arctangent of a number. Syntax: - Atn(Numeric_Exp) Remarks: - Atn() is inverse trigonometric function of Tan(). Debug.Print(1 / Math.Atan(1.3)) 'Returns ) Cos (): - Usage: - Cos() returns a Double specifying the cosine of an angle. Syntax: - Con(Numeric_Exp) Debug.Print(1 / Math.Cos(1.3))'Returns ) Exp (): - Usage: - It returns a double-precision number that specifying e raised to the specified power (The natural logarithm, which has a base of about ) Syntax: - Exp(Numeric_Exp) Debug.Print(Math.Exp(14)) 'Returns Debug.Print( ^ 14) 'Returns Prepared By: Ankit Shah Page 8

9 5) Fix (): - Usage: - It returns only integer portion of a given numeric expression. If number is Null, Null is returned. Syntax: - Fix (Numeric_Exp) Private Sub Form_Click () Debug.Print(Fix(1.9)) 'Returns 1 Debug.Print(Fix(-1.9)) 'Returns 1 Debug.Print(Fix(-1.2)) 'Returns 1 6) Int (): - Usage: - It returns only integer (smallest integer number nearest to given number) portion of a given valid double numeric expression. If number is Null, Null is returned. Syntax: - Int (Numeric_Exp) Private Sub Form_Click () Debug.Print Int (1.9) 'Returns 1 Debug.Print Int (-1.9) 'Returns 2 Debug.Print Int (-1.2) 'Returns 2 7) Log (): - Usage: - It returns a double specifying the natural logarithm of a given valid double numeric expression. Syntax: - Log (Numeric_Exp) Private Sub Form_Click () Debug.Print(Math.Log( )) 'Returns 14 Debug.Print(Math.Log(14) / Math.Log(10)) 'Returns ) Rnd (): - Usage: - It returns Single containing random number between 0 and 1. You can produce random numbers in a given range multiplying the rang to the function as shown in the example. Syntax: - Rnd [(Numeric_Exp)] Return Values: - If number is Rnd generates ===================================================== Less than zero The same number every time, using number as the seed. Greater than zero The next random number in the sequence. Equal to zero The most recently generated number. Not supplied The next random number in the sequence. Prepared By: Ankit Shah Page 9

10 For I = 0 To 10 Debug.Print (Rnd(-1)) 'Returns same no every time Debug.Print (Rnd(0)) 'Returns same no as generated form previous Rnd() Next 9) Sign (): - Usage: - It returns integer indication the sign of given numeric expression. Syntax: - Sign(Numeric_Exp) Returns values are: If number is Sgn() Returns ============================ Greater than zero 1 Equal to zero 0 Less than zero -1 Debug.Print(Sign(1)) 'Returns 1 Debug.Print(Sign(0)) 'Returns 0 Debug.Print(Sign(-4.5)) 'Returns 1 10) Sin (): - Usage: - Sin() function returns a Double specifying the sine of an angle. Syntax: - Sin(Numeric_Exp) Debug.Print (1 / Sin(1.3)) 'Returns ) Sqrt(): - Usage: - it returns square root of a given numeric expression. Syntax: - Sqr(Numeric_Exp) Example:- Debug.Print (Sqrt(4)) 'Returns 2 12) Tan(): - Usage: - It returns a Double specifying the tangent of an angle. Syntax: - Tan(Numeric_Exp) Remark: - The required number argument is a Double or any valid numeric expression that express an angle in radians. Prepared By: Ankit Shah Page 10

11 Debug. Print (1 / Tan(1.3)) 'Returns Date and Time Handling Statements & Functions: - 1) Date Statement: - Usage: - Date statement is used to get or change the current system date Syntax: - Today Private Sub Form_Click(ByVal sender As System.Object, ByVal e As TextBox1.Text = Today Returns current Date 2) Time Statement: - Usage: - Time statement is used to get or change the current system Time. Syntax: - TimeOfDay Private Sub Form_Click(ByVal sender As System.Object, ByVal e As TextBox1.Text = TimeOfDay Returns current Time 3) Now Statement: - Usage: - Now statement is used to get the current date and time simultaneously but you can t assign any expression to Now as Date and Time statement. If you want to modify you have to use Date and Time statement. Syntax: - [variable_name=] Now Private Sub Form_Click(ByVal sender As System.Object, ByVal e As Debug.Print Current date and time = ; Now Returns current date & time 4) Second(): - Usage: - Second() returns integer specifying a number between 0 to 59, representing the second of the minute. Syntax: - Second( Time_Exp) Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As TextBox1.Text = Second(TimeOfDay) Returns second from time Prepared By: Ankit Shah Page 11

12 5) Minute(): - Usage: -Minute() returns integer specifying a number between 0 to 59 representing the minute of the hour. Syntax: -Minute (Time_Exp) Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As TextBox1.Text = Minute(TimeOfDay) Returns minute from time 6) Hour() : - Usage: - Hour() returns integer specifying a number between 0 to 23 representing the hour of the day. Syntax: - Hour ( Time_Exp) Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As TextBox1.Text = Hour(TimeOfDay) Returns hour from time 7) DateSerial(): - Usage: -DateSerial function returns Date for a specified year, month and day as integer into system date format. Syntax: - DateSerial (year, month, day) Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As Debug.Print DateSerial(2, 8, 20) 'Returns 08/20/02 (mm/dd /yyyy) 8) TimeSerial(): - Usage: - TimeSerial function returns Time for a specified hour, minute and second as integer into system Time format. Syntax: - TimeSerial (hour, minute, second) Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print (TimeSerial(2, 8, 20)) 'Returns 2:08:20 AM Debug.Print (TimeSerial(20, 8, 20)) 'Returns 8:08:20 PM 9) DateValue(): - Usage: - DateValue function returns date into system date format, which requires argument in string that represents date from January (Jan) 1,100 through December (Dec) 12, If the year part of date is omitted DateValue function uses the current year from your system, but you can not omit day or month part Prepared By: Ankit Shah Page 12

13 Syntax: - DateValue (Date_Exp) Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print (DateValue("January, ")) 'Returns 1/12/2002 Debug.Print (DateValue("12 Jan")) 'Returns 1/12/ ) TimeValue(): - Usage: - The TimeValue() returns the time into system format which requires argument in string that represetns time from 0:00:00(12:00:00 A.M.) through 23:59:59(11:59:59 P.M.). If minute or second part is omitted, it uses 00. If minute and second both are omitted A.M. or P.M. must be there. Syntax : - TimeValue( Time_Exp) Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print (TimeValue("12 PM")) 'Returns 12:00:00 PM Debug.Print (TimeValue("11:10")) 'Returns 11:10:00 AM Debug.Print (TimeValue("17:10")) 'Returns 5:10:00 PM 11) DateAdd(): - Usage: - DateAdd function is used to add or subtract a specified time interval from a date or time. Syntax: -DateAdd(Interval, Number, Date) Parts of the syntax: - Parts Description ======================================================= Interval It is string expression that is interval of time you want to add. The argument as interval can be any of following. Interval argument Description yyyy Year q Quarter m Month y Day of year d Day w Weekday( Day of Week) ww Week h Hour n Minute s Second Prepared By: Ankit Shah Page 13

14 Number It is numeric expression that is the number of intervals you want to add. It can be positive or negative. Date It is date to which the interval is added. i. Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Dim Dt,Tm As Date Dt = "08/20/2002" Tm = "02:30:35 PM" Debug.Print (DateAdd("yyyy", 1, Dt)) ' Returns 8/20/2003 Debug.Print (DateAdd("q", 1, Dt)) ' Returns 11/20/2002 Debug.Print (DateAdd("m", 1, Dt)) ' Returns 9/20/2002 Debug.Print (DateAdd("y", 1, Dt)) ' Returns 8/21/2002 Debug.Print (DateAdd("d", 1, Dt)) ' Returns 8/21/2002 Debug.Print (DateAdd("w", 1, Dt)) ' Returns 8/21/2002 Debug.Print (DateAdd("ww", 1, Dt)) ' Returns 8/27/2002 Debug.Print (DateAdd("h", 1, Tm)) ' Returns 3:30:35 PM Debug.Print (DateAdd("n", 1, Tm)) ' Returns 2:31:35 PM Debug.Print (DateAdd("s", 1, Tm)) ' Returns 2:30:36 PM 12) DateDiff(): - Usage: - DateDiff function returns intervals between given two date or time. Syntax: - DateDiff (Interval, Date1, Date2 [, FirstDayOfWeek [,FirstWeekOfYear ]]) Parts of the syntax: - Parts Description =============================================== Interval Same as DateAdd() Date1, Date2 Two date or time you want to use in calculation. (Time1,Tiem2) FirstDayOfWeek A constant (listed below) that specifies the first day or FirstWeekOfYear the week. If not specified, Sunday is by default. A constant (listed below) that specifies the first week of the year. If not specified the first week is assumed to be the week in which January 1 occurs. Constants related to argument FirstDayOfWeek are : Constant Value Description ===================================================== vbsunday 1 Sunday (Default vbmonday 2 Monday vbtuesday 3 Tuesday vbwednesday 4 Wednesday Prepared By: Ankit Shah Page 14

15 In-Built Functions vbfriday 6 Friday vbsaturday 7 Saturday Constants related to argument FirstWeekOfYear are: Constant Value Description ===================================================== vbusesystem 0 Use the NLS API setting. vbfirstjan1 1 Start with the first week in which January 1 occurs. (default) vbfirstfourdays 2 Start with the first week that has at least four days in the new year. vbfirstfullweek 3 Start with first full week of the year. ii. Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print (DateDiff("yyyy", "1/04/2000", "1/01/2001",, FirstWeekOfYear.Jan1)) 'Returns 1 Debug.Print (DateDiff("ww", "7/20/2000", "7/20/2001", vbsunday)) 'Returns 52 Debug.Print (DateDiff("w", "7/20/2000", "7/20/2001")) 'Returns 52 Debug.Print (DateDiff("ww", "7/20/2000", "7/20/2001", FirstDayOfWeek.Monday)) 'Returns 52 Debug.Print (DateDiff("h", "10:20:30", "12:20:30")) 'Returns 2 Debug.Print (DateDiff("n", "10:20:30", "12:20:30")) 'Returns 120 Debug.Print (DateDiff("s", "10:20:30", "12:20:30")) 'Returns 7200 Debug.Print (DateDiff("h", "10 AM", "12 PM")) 'Returns 2 13) DatePart(): - iii. Usage: - It returns an integer containing the specified part of a given date or time, so you can calculate the day of the week or the current passed hour. Syntax: - DatePart (Interval, Date [,FirstDayOfWeek [, FirstWeekOfYear]]) Parts of the syntax: - Explained in DateAdd function. Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print DatePart("yyyy", "07/20/2001") 'Returns 2001 Debug.Print DatePart("m", "07/20/2001") 'Returns 7 Debug.Print DatePart("d", "07/20/2001") 'Returns 20 Debug.Print DatePart("ww", "07/1/2001",, vbfirstfullweek) 'Returns 26 Debug.Print DatePart("ww", "07/1/2001") 'Returns 27 Prepared By: Ankit Shah Page 15

16 Data Verification / Logical Functions: - 1) IsDate (): - Usage: - It returns True if the expression is a valid date, otherwise it returns False. The range of valid date is January (Jan) 1, 100 A.D. through December (Dec) 31, 9999 A.D. Syntax: - IsDate (Expression) Example : - Private Sub Button2_Click (ByVal sender As System.Object, ByVal e As Debug.Print IsDate("6/12/2002") 'Returns True Debug.Print IsDate("13/13/2002") 'Returns False 2) IsNumeric (): - Usage: - IsNumeric() returns True if the entire expression is numeric otherwise it returns False: Syntax: - IsNumeric (Expression) Exmple: - Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As Debug.Print(IsNumeric("45")) 'Returns True Debug.Print(IsNumeric("Age 45")) 'Returns False 3) IsArray(): - Usage: - IsArray() returns True if the expression is array otherwise it returns False: Syntax: - IsNumeric (Expression) Exmple: - Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As Dim a(10) As Integer Debug.Print(IsArray(a)) Returns True 4) LBound(): - Usage: - LBound() returns the lower boundary of an array. Syntax: - LBound(Array_variable) Exmple: - Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As Dim a(10) As Integer Debug.Print(LBound(a)) Retuns 0 Prepared By: Ankit Shah Page 16

17 5) UBound(): - Usage: - LBound() returns the lower boundary of an array. Syntax: - UBound (Array_variable) Exmple: - Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As Dim a(10) As Integer Debug.Print(UBound(a)) Returns 10 Prepared By: Ankit Shah Page 17

Phụ lục 2. Bởi: Khoa CNTT ĐHSP KT Hưng Yên. Returns the absolute value of a number.

Phụ lục 2. Bởi: Khoa CNTT ĐHSP KT Hưng Yên. Returns the absolute value of a number. Phụ lục 2 Bởi: Khoa CNTT ĐHSP KT Hưng Yên Language Element Abs Function Array Function Asc Function Atn Function CBool Function CByte Function CCur Function CDate Function CDbl Function Chr Function CInt