Transcript
Front-End And Back-End
Form / Interface / Front-End
StudentRoll Number Name Address Phone1 Raj c-65, hari nagar 251266332 Amit a-45, Ramesh ngr. 251652633 Rahul c-96, Janak puri 25545298
Table / Relation / Back-End
DataTypes in VB
Datatype Storage size Range 1. Byte 1 byte 0-2552. Boolean 2 bytes True or False3. Integer 2 bytes -32768 to +327674. Long 4 bytes -2147483648 to +2147483647 5. Single 4 bytes
Roll Number
Name
Address
Phone
4
Himanshu
WZ-45, Hari Nagar
9213222920
Save Delete Search
6. Double 8 bytes7. Currency 8 bytes8. Decimal 14 bytes9. Date 8 bytes Jan 1, 100 to
Dec 31, 999910. Object 4 bytes Any object reference11. String (variable length) 10 bytes + string length 0 to approx. 2 billion12. String (fixed length) length of string 1 to approx. 65,400 13. Variant (numeric) 16 bytes 14. Variant (text) 22 bytes + string length
Declaring & initializing Variables
Dim Num as integerNum = 2557
Or Num = -235 Or Num = 32 + 7 - 3
Dim Age as byteAge = 73
Or Age = 12Dim Name as string …. variable length string Name = “raj”Dim Name as string * 15 …. fixed length stringName = “raj”Dim Address as stringAddress = “A-45, janak puri“Dim price as singlePrice = 75.80
Or Price = 75.25 - 1.85Dim x as Booleanx = true
Or x = false Or x= 5<2 …. false
dim doj as datedoj = #8-15-2005#dim x as datex = #12:45 PM#dim p as variant
Or dim p …. (by default variant)p = “raj”
Or p = 45 Or p = #8-15-2005# Or p = true Or p=45.7
Dim a, b, c as integer
Variant variables
Literals
String literals:“raj”, “a-45, hari nagar”, “845.73”, “8-15-2005”
Boolean literals:True, false
Date / Time literals:#8-12-2005#, #1:45 AM #
Single / Double literals:12.5#, -13.80 , +0.73, 85.2!
byte / integer / long literals:+45, -33, 0, 48, 128, 85%
Type declaration characters
% Integer$ string@ currency& long# double! single
Dim x% declares x as integer variableDim p$ declares p as string variableDim n# declares n as double variable
CommentsThe word REM or symbol (‘) tells the visual basic that everything on that line
following REM or (‘) is not the code, it is a comment and should be ignored by the compiler. REM can appear only in the beginning of the line but apostrophe (‘) can appear after a statement also.
Example:Dim x% ‘declares x as integer variable REM example of a comment.
Variable Default Values
Datatype Default Values Integer 0 Long 0 Single 0
Double 0 String “ “ blanks/null Boolean false Variant empty Date 0 Currency 0
Implicit & Explicit Variables Declaration
Dim x, y variant variablesP=100 implicit variable (variant)Dim m as integer explicit variable Option explicit only explicit variables can be used
Defining Named Constants
Syntax:[public / private] const <constantname> [as type] = expression
Examples:const pi = 3.14public const a as integer = 9const jdate = #2/1/05#public const nm = ”raj”public const x = 14, nm = “raj”
Operators1. Arithmetic Operators2. String or Concatenation Operators3. Comparison Operators4. Logical Operators
Arithmetic operators
+, -, *, /, \ , mod, ^2 + 5 …. 7“daljeet” + ”singh” …. “daljeetsingh”“91” + “6” …. “916”5/2 …. 2.511/3 …. 3.665\2 …. 211\ 3 …. 35 mod 2 …. 111 mod 3 …. 22 ^ 3 = 23 …. 83 ^ 3 = 33 …. 27
Concatenation operators(&)“Daljeet“ & “singh“ …. “Daljeetsingh”
Comparison operators= 2=3 …. false< > 9< >7 …. true> 8>5 …. true>= 5>=5 …. true< 91<15 …. false<= 9<=8 …. false
Logical Operators
AND, OR, NOT, XOR(5 > 7 AND 9 <= 81) …. falsefalse true
Truth TableA B A AND B A OR B A XOR B NOT A NOT BFalse False False False False True True False True False True True True FalseTrue False False True True False TrueTrue True True True False False False
The Print StatementSyntax:
Print “Message Text“Print constant / variable / expression
Example:Print “this is visual basic”Print 10A = 30Print APrint A * 2 / 3
Print using comma:Print 2, 3, 4, 5, 6
Output:2 3 4 5 6
Print using semicolon:Print 1;2;3;4
Output: 1234
print “hello“;“friends“Output:
hellofriends
Controls & their Properties
Control Name Property ValueLabel Name
Appearance 0 – flat1 – 3D
Alignment 0 – left justify1 – right justify2 – center
Autosize true / falseBackcolorBackstyle 0 – transparent
1 – opaqueBorderstyle 0 – none
1 – fixed singleCaptionEnabled true / falseFontForecolorHeightLeftTooltiptextTopVisible true / falseWidth
Control name Property ValueTextbox Name
Alignment 0 – left1 – right2 – center
BackcolorEnabled True / falseFontForecolorHeightLeftMaxlengthMultiline True / falsePasswordcharScrollbars 0 – none
1 – horizontal2 – vertical3 – both
Width
Borderstyle 0 – none1 – fixed single
Appearance 0 – flat1 – 3D
TextTooltiptextTopVisible true / false
Control Name Property ValueCommand button Name
Appearance 0 – flat1 – 3D
BackcolorCaptionDisabledpictureDownpictureEnabled true / falseFontHeightLeftPictureStyle 0 – standard
1 – graphicalTooltiptextTopVisible true / falseWidth
Control Name Property ValueFrame Name
BackcolorBorderstyle 0 – none
1 – fixed singleCaptionEnabled true / falseFontForecolorHeightLeftTooltiptextTopVisible true / falseWidth
Control Name Property ValueCheckbox Name
Allignment 0 – left1 - right
BackcolorCaptionDisabledpictureDownpictureEnabled true / falseFontForecolorHeightLeftPictureStyle 0 – standard
1 – graphicalTooltiptextTopValue 0 – unchecked
1 – checkedVisible true / falseWidth
Control Name Property ValueOptionbutton Name
Allignment 0 – left1 - right
BackcolorCaptionDisabledpictureDownpictureEnabled true / falseFontForecolorHeightLeftPictureStyle 0 – standard
1 – graphicalTooltiptextTopValue true / falseVisible true / falseWidth
Control Name Property ValuePicturebox Name
Align 0 - None 1 – Align top2 – Align bottom3 – Align left4 – Align right
Autosize True / falseBackcolorBorderstyle 0 – none
1 – fixed singleEnabled true / falseFontForecolorHeightLeftPictureTooltiptextTopVisible true / falseWidth
Control Name Property ValueImage Name
Borderstyle 0 – none1 – fixed single
Enabled true / falseHeightLeftPictureStretch true / falseTooltiptextTopVisible true / falseWidth
Control Name Property ValueCombo box Name
BackcolorEnabled True / falseFontForecolorHeightLeftList
Style 0 – Drop down combo1 – simple combo2 – drop down list
TextTooltiptextTopVisible true / falseWidth
Control Name Property ValueListbox Name
BackcolorEnabled True / falseFontForecolorHeightLeftListMultiselect 0 – none
1 – simple2 – extended
Style 0 – standard1 – checkbox
TooltiptextTopVisible True / FalseWidthText
Control Name Property ValueHscrollbar / vscrollbar Name
Enabled True / falseHeightLeftMax 32767Min 0TopValueVisible True / falseWidth
Control Name Property ValueDriveListbox Name
BackcolorEnabled True / falseFontForecolorHeight
LeftTooltiptextTopVisible True / falseWidthDrive
Control Name Property ValueDirectory list box Name
BackcolorEnabled True / falseFontForecolorHeightLeftTooltiptextTopVisible True / falseWidthPath
Control Name Property ValueFile list box Name
BackcolorEnabled True / FalseFontForecolorHeightLeftMultiselect 0 – none
1 – simple2 – extended
PatternTooltiptextTopVisible True / falseWidthPath
Control Name Property ValueShape Name
BackcolorBackstyle 0 – transparent
1 – opaqueBordercolorFillcolorHeightLeft
Shape 0 – rectangle1 – square2 – oval3 – circle4 – rounded rectangle5 – rounded square
TopVisible True / falseWidthFillstyle 0 – solid
1 - transparent
Control Name Property ValueTimer Name
Enabled True /FalseIntervalLeftTop
Control Name Property ValueForm Name
BackcolorCaptionEnabled True / falseFontForecolorHeightLeftMdichild True / false Maxbutton True / falseMinbutton True / falsePictureTopVisible True / FalseWidthWindowstate 0 – normal
1 – minimized2 - maximized
Events Event refers to the occurrence of an activity.
Some useful events
1. Click:- When the user clicks the primary mouse button on an object.2. Change:- When the user modifies text in combo box or text box.3. Gotfocus:- When an object receives focus.4. Lostfocus:-When an object loses focus.5. Keypress:- The user presses and releases a keyboard key while an object has
focus.6. Keyup:- When the user releases a keyboard key when an object has focus.7. Dragdrop:- The use drags an object to another location.8. Dragover:- The user drags an object over another control.9. Form_load: - When the form loads for execution in memory.
Setting the Properties
The controls that you draw on your form, have some properties associated with them. The properties can be set by two different ways.
1. At design time2. At run time.
1. Properties can be set at design time using properties window.
2. Setting properties at run time.
Setting the Alignment property
Example:Label1.alignment = 0
OrText1.alignment = 1
Setting Appearance property
Example:Label1.appearance =1
OrCommand1.appearance = 1
OrOption1.appearance = 0
Setting Autosize PropertyExample:
Label1.autosize = true
OrLabel1.autosize = false
OrPicture1.autosize = true
Setting the backcolor propertyExample:
Label1.backcolor = RGB(100, 125, 190)
0-255 (red) 0-255(green) 0-255( blue)Or
text1.backcolor = RGB(50, 50, 100)Or
text1.backcolor = VbRed
Setting Backstyle PropertyExample:
Label1.Backstyle = 0Or
Label1.backstyle = 1
Setting Borderstyle PropertyExample:
Label1.Borderstyle = 0Or
Label1.Borderstyle = 1
Setting the Enabled PropertyExample
Text1.enabled = trueOr
Label1.enabled = false
Setting caption propertyExample:
Label1.caption = “this is my name”Or
Command1.caption = “click me”
Setting forecolor propertyExample:
Label1.forecolor = RGB( 100, 255, 70)Or
Label1.forecolor = VbBlue Setting Height Property
Example:Label1.height = 100
OrCommand1.height = 200
Setting the tooltiptext propertyExample:
Text1.tooltiptext = “This is a text box”
Setting the text propertyExample:
Text1.text = “Amit sharma”
Setting the visible propertyExample:
Label1.visible = trueOr
Text1.visible = false
Setting the width propertyExample:
Text1.width = 250Or
Command1.width = 100
Setting the style propertyExample:
Command1.style = 0Or
Option1.style = 1
Setting the picture propertyExample:
Check1.picture = loadpicture ( “c:\abc.gif”)Or
Command1.picture = loadpicture ( “c:\abc.gif”)Or
Option1.picture = loadpicture ( “c:\abc.gif”)Or
Picture1.picture = loadpicture ( “c:\abc.gif”)
Setting the disabledpicture and downpicture propertyExample:Command1.disabledpicture = loadpicture(“c:\abc.gif”)OrCommand1.downpicture = loadpicture(“c:\abc.gif”)
Setting the value property of checkboxExample:
Check1.value = 0Or
Check1.value = 1
Setting the value property of option buttonExample:
Option1.value = trueOr
Option1.value = false
Setting the stretch property of image controlExample
Image1.stretch = trueOr
Image1.stretch = false
Setting the max/min property of Hscrollbar / VscrollbarExample
Hscroll1.max = 100
Hscroll1.min = 1
Vscroll1.max = 100
Vscroll1.min = 1 Setting the fillstyle and fillcolor property
Example:Shape1.fillstyle = 0
Shape1.fillcolor = RGB(100, 150, 200) Setting the Shape Property of Shape control
Example:Shape1.shape = 1
OrShape1.shape = 3
Setting the windowstate property of formExample:
Form1.windowstate = 0Or
Form1.windowstate = 1
Some Examples:Example1:- Loading a picture in the picture box at run time.
Picture Box
Command Button (cmdload)
Private sub cmdload_click()Picture1.picture = loadpicture (“c:\abc.gif”)
End sub
Example2: – Loading a picture in the image control at run time.
Image control(image1)Command Button( cmdload )
Private sub cmdload_click()Image1.picture = loadpicture (“c:\abc.gif”)
End sub
Example3: List Box
ListBox (list1)
Load
Add
Delete
Clear
Listcount
Listindex
Display
Enter Your Name
Private sub cmdadd_click()List1.additem text1.text
End sub
Private sub cmddel_click()List1.removeitem list1.listindex
End sub
Private sub cmdclear_click()List1.clear
End sub
Private sub cmdcount_click()Msgbox List1.listcount
End sub
Private sub cmdindex_click()Msgbox list1.listindex
End sub
Private sub cmddisp_click()Msgbox list1.text
End sub Adding an item in the list box
List1.additem “Ravi”List1.additem text1.text
Removing an item from the list boxList1.removeitem 0List1.removeitem list1.listindex
Example 4: Hscrollbar / Vscrollbar application
Hscroll1
Command Button (cmdsum) vscroll1
Private sub hscroll1_change()Text1.text = hscroll1.value
End sub
Private sub Vscroll1_change()Text2.text = vscroll1.value
End sub
Private sub cmdsum_click( )Dim a as integer, b as integera = val (text1.text)b = val (text2.text)text3.text = a + b
End sub
Example 5 : Shape Control ApplicationShape Control (shape1)
Sum
Private sub cmdrect_click( )Shape1.shape = 0
End sub
Private sub cmdsquare_click( )Shape1.shape = 1
End sub
Private sub cmdoval_click( )Shape1.shape = 2
End sub
Private sub cmdcircle_click( )Shape1.shape = 3
End sub
Private sub cmdroundrect_click( )Shape1.shape = 4
End sub
Private sub cmdroundsquare_click( )Shape1.shape = 5
End sub
Example 6 : Drive, Directory and file list box Drive1 directory1 file1
Rectangle Square Oval
Circle Rounded Rectangle
Rounded square
Private sub drive1_change( )Dir1.path = drive1.drive
End sub
Private sub dir1_change( )File1.path = dir1.path
End sub
Private sub text1_change( )File1.pattern = text1.text
End sub
Example 7: Timer application. Label1
Timer1 cmdreset
Set the following properties:Timer1.interval = 1000Label1 - > font = MS sans serif, bold, 18
C:
C:\ Program Files ………. ………. ……….
Abc.dllRmn.dllPqr.exe………………………
Enter the pattern
Reset
Dim I as integerPrivate sub cmdreset_click( )
I = 0End sub Private sub timer1_timer ( )
Label1.caption = iI = I + 1
End sub
Example 7: Option Button Application.
lblgrade cmdgrade
Private sub cmdgrade_click( )If optone.value = true then
Lblgrade.caption = “ The grade is A”Else if opttwo.value = true then
Lblgrade.caption = “ The grade is B”Else if optthree.value = true then
Lblgrade.caption = “ The grade is C”Else if optfour.value = true then
Lblgrade.caption = “ The grade is D”End if
End sub
Private sub form_load( )Optone.value = falseOpttwo.value = false
90
70
80
60
Click
Percentage
Optthree.value = falseOptfour.value = false
End sub
Manipulating forms
Setting the startup form
To change the startup form1. Goto project menu - > project peoperties2. Select General Tab3. In startup object listbox select the form4. Click Ok
Loading and unloading the forms
Load form1Unload form1Unload me
Showing and Hiding forms
Form1.showForm2.showForm1.hideMe.hide
Assigning the Access keyCommand buttons can be used by clicking on them or by pressing the alt + <
access key >. To assign a keyboard access key to command button place ampersand( &) in front of the letter that is to be used as access key, while setting the caption property of the command button.
Control Structures in VB
Control Flow:
1. Sequence2. Selection3. Iteration
The if statement:Syntax:
if (condition) thenstatements
end if
Example:
If (a>10) thenPrint ”Raj”
End if
The if…. Then… else statementSyntax:
If (condition) thenstatements
elsestatements
End ifExample: Text1
cmdresult
Private sub cmdresult_click( )Dim m as integerm = val (text1.text)if (m >= 40) then
print ”you are passed”else
print ”you are failed”end if
End sub
Enter the marks
Result
If …then… else if statementSyntax:
If (condition) thenstatements
else if (condition) thenstatements
else if (condition) thenstatements
.
.
.else
statementsEnd if
Example:
Text1
cmdprintday
Private sub cmdprintday_click( )Dim x as integerX = val(text1.text)If(x = 1) then
Msgbox ”Sunday”else if (x = 2) then
Msgbox ”Monday”else if (x = 3) then
Msgbox ”Tuesday”else if (x = 4) then
Msgbox ”Wednesday”else if( x = 5) then
Msgbox ”Thursday”else if (x = 6) then
Enter a number
Print day
Msgbox ”Friday”else if (x = 7) then
Msgbox ”Saturday”Else
Msgbox ”Invalid choice”End if
End sub
Nested ifsExample:
If ( x > 7) thenIf( y <= 8) then
Print ”Ravi”Else
Print ”Amit”End if
ElseIf (P <> 71) then
Print ”vishvas”Else
Print ”Raj”End if
End if
Compound if:Example:If ( x > 7 AND y <> 75) then
Print ”Vicky”Else
Print ”Raj”End if
Example:If( x >= 91 OR p <> 83) then
Print ”Rishabh”Else
Print ”Amrita”End if
The iif( ) function:Syntax:
iif(condition, value1, value2)Example:
Dim num1 as integer, num2 as integer, big as integer
Num1 = 7Num2 = 81Big = iif (num1 >= num2, num1, num2)
Select case statement: If Select case 1. if x = 1 case12. if x > 7 case is > 73. if x < 7 case is < 74. if x >= 7 AND x <= 20 case 7 to 20
Example 1: Text1
cmdprintday
Private sub cmdprintday_click( )dim m as integerm = val( text1.text )select case m
case 1: Msgbox ”Sunday”case 2
Msgbox ”Monday”case 3
Msgbox ”Tuesday”case 4: Msgbox ”Wednesday”case 5: Msgbox ”Thursday”case 6: Msgbox”Friday”case 7: Msgbox”Saturday”case else
Msgbox ”Invalid choice”End select
End sub
Enter a number
Print day
Example 2: Text1
cmdresult
Private sub cmdresult_click( )Dim m as integerM = val( text1.text )Select case m
Case is < 50Msgbox ”Fail”
Case is < 60: Msgbox ”Grade B”
Case is < 75: Msgbox ”Grade A”
Case else: Msgbox ”Grade A+”End select
End sub
Example 3:txtmonth
cmdnod
Private sub cmdnod_click( )Dim n as integer
Enter the marks
Result
Enter the month no.
No. of days
n = val ( txtmonth.text )select case n
case 1,3,5,7,8,10,12Msgbox ”31 days in the month”
case 2Msgbox ”28 days in the month”
Case 4,6,9,11Msgbox ”30 days in the month”
End selectEnd sub
Looping Structures:1. For…Next2. Do loop
(a) Do while…loop(b) Do…loop while(c ) Do until…loop(d) Do…loop until
3. while…wend
1. For…next Example:
For i = 1 to 10 step 1Print “Raj”
Next iExample:
For i = 7 to 22 step 2Print “abc”
Next i
Example:For x = 17 to 1 step -3
Print “raj” Next x
2.(a) Do while…loopExample:
x = 1Do while (x < = 10)
Print “xyz”x = x + 1
loop
Example:x = 10Do while (x > = 1)
Print “xyz”x = x - 1
loop
Example:x = 1Do while (x < = 20)
Print “raj”x = x + 2
loop
2.(b) Do…loop whileExample:
x = 1do
print “ABC”x = x + 1
loop while (x <= 10)Example:
x = 10do
print “raj”x = x - 1
loop while (x >= 1)
2.(c) Do until…loop
While Untilx < 10 x >= 10x <= 10 x > 10x > 1 x <= 1x >= 1 x < 1x < >1 x = 1x = 1 x <> 1
Example:x = 1do until x > 10
print “Raj”x = x + 1
loopExample:
x = 10
do until x < 1print “Raj”x = x - 1
loop
2.(d) Do…loop until
Example:x = 1do
print “Raj”x = x + 1
loop until > 10
Example:x = 10do
print “Raj”x = x - 1
loop until x < 13. While wend
Example:x = 1while x <= 10
print “raj”x = x + 1
wend
Example:x = 10while x >= 1
print “raj”x = x - 1
wend
Nested loopsExample:
for I = 1 to 3 step 1for j = 1 to 5 step 1
print "raj"next j
next iExample:
i=1do while i<=3
j = 1do while j<=5
print "raj"j=j+1
loopi=i+1
loop
Exiting from loops Exit For Exit DoExample: (Exit For) for i=1 to 10 step 1
if (I = 7) then Exit for
End if print i next i
Example: (Exit do) x=1
do while x<=10 if(x=7) then
Exit doEnd ifprint xx=x+1
loop Arrays
Array is a collection of variables of same type that are referenced by a common name.
Example: Private sub Command1_Click()
dim a(4) as integerdim i as integerfor i=0 to 4 step 1
a(i) = inputbox "enter a number "next i
for i=0 to 4 step 1
print a(i)next i
End Sub
dim x(1 to 5) as integerdim x(5 to 9) as integer
Redim statementExample: Private sub Cmdprint_Click( )
dim a( ) as integerdim i as integerredim a(4)for i=0 to 4 step 1
a(i) = inputbox "Enter a number"next ifor i=0 to 4 step 1
print a(i)next iredim a(9)print "array after re-dimensioning "for i=0 to 9 step 1
print a(i)next i
End sub Preserve statement
Redim preserve a(9)
Procedures & Functions
Types of Procedures
1. Sub Procedures2. Function Procedures3. Property Procedures
1. Sub Procedures: A sub procedure or subroutine or sub is a procedure that performs a specific task but does not return a value.
Example: Procedure without arguments
cmdprintmessagePrivate sub cmdprintmessage_click( ) print "Raj" print "Daljeet" disp or call disp print “ravi” print "kailash" call disp print "vishal"End subPrivate sub disp( ) print "Harish" print "Manish" print "Vicky"End sub
Example: Procedures with arguments
text 1
text 2
text 3
cmdsumPrivate sub cmdsum_click( )
dim x as integer, y as integerx = val (text1.text)y = val(text2.text)call findsum (x, y) or findsum x, yfindsum x …. Errorfindsum x, 5, y …. Error
End subPrivate sub findsum (n as integer, m as integer)
text3.text = n + mEnd sub
2. Function Procedures: A function is a procedure that performs a specific task and returns a value.
Types of Functions
Print message
Enter a number
Enter second number
Result is
sum
1. User Defined Functions2. Built in Functions or Library Functions
Example:
Text1
Text2
Text3
cmdsum
Private sub cmdsum_click( )dim x as integer, y as integer, z as integerx = val(text1.text)y = val(text 2.text)z = findsum(x, y)text3.text = z
End subPrivate function findsum (n as integer, m as integer) as integer
findsum = n + mEnd function
Passing Parameters to Procedures1. Call by Value (pass by value) ……………….Byval2. Call by Reference (pass by reference) ..……ByrefExample:
cmdprint
Private sub cmdprint_click( )dim x as integer x=5print x …. 5call change(x) or change x …. 100print x …. 100
End subPrivate sub change (Byref n as integer)
n=100
Enter a number
Enter a second number
Result is
Sum
print nEnd sub
Using Optional Arguments
Text1
Text2
Text3
cmdsum
Private sub cmdsum_click( )dim x as integer, y as integerx = val(text 1.text)y = val(text 2.text)findsum x, yfindsum xfindsumfindsum 2, y, 5 …. error
End subPrivate sub findsum (optional n as integer = 70, optional m as integer = 80)
text3.text = n + mEnd sub
Exiting from Procedures1. Exit Sub2. Exit Function
text1
cmdcheck
Private sub cmdcheck_click( )dim x as integer x = val(text1.text)call samplepro(x)
End subPrivate sub samplepro (n as integer )
if (n > 50) thenmsgbox "you have got a car"
else
Enter first number
Enter second number
Result is
sum
Enter a no.
check
Exit subEnd if
End sub
Library Functions String Functions:
1. Lcase and Ucase FunctionsPrint Ucase(“hello”) - HELLOPrint Lcase (“HELLO”) - helloText1.text = Ucase(text1.text)Text1.text = Lcase(text1.text)
2. Len Functiondim x as integerx = len(“raj”)print x - 3x = len(text1.text)print xprint len(“Rajeev”) - 6
3. Trim, Ltrim, and Rtrim functionsText1.text = Ltrim(“ daljeet”)Text1.text = Rtrim(“sandeep ”)Text1.text = trim(“ amit arora ”)Text1.text = trim(text1.text)Text1.text = rtrim(text1.text)
4. Left and Right functionsdim n as string, m as stringm = “daljeet”n = right(m, 4)print n - jeetm = “raj arora”print left (m,3) - raj
5. Mid functiondim x as string, y as stringx = “raj kumar arora”y = mid (x, 5, 5)print y - kumar print (x,11, 5) - arora
6. Instr functiondim searchstring as string, searchchar as string, mypossearchstring = “XXpXXpXXPXXP”searchchar = “P”mypos = instr (4, searchstring, searchchar, 1) - 6
mypos = instr(1, searchstring, searchchar, 0) - 9mypos = instr(searchstring, searchchar) - 9mypos = instr(searchstring, ”w”) - (0) not found
7. Space Functiondim p as stringp = “raj” & space(10) & ”puri”
print p - raj puri
8. String Functiondim x as string x = string(10, ”a”)print x - “aaaaaaaaaa”x = string (5, ”ABC”)print x - “AAAAA”
9. Str Functiondim x as string, y as stringx = str(1205) - “1205”y = str(1305) - “1305”print 12 + 15 - 27print str(12) + str(15) - 1215print “12” + “15” - 1215
10.Asc Functiondim x as integerx = asc(“A”)print x - 65print asc(“Abc”) - 65x = asc(“a”)print x - 97ASCII ValuesAmerican Standard Codes For Information Interchange.“A” to “Z” - 65 to 90“a” to ”z” - 97 to 122“0” to “9” - 48 to 57
11.Chr Functiondim x as stringx = chr(65)print x - Aprint chr(66) - B
x = chr(98)print x - b
12.Strreverse FunctionDim x as stringx = “Neeraj“
Print strreverse(x) - jareeNPrint strreverse (“neeraj”) - jareenText1.text = strreverse(text1.text)
Numeric Functions1. Int & Fix Functions
print int(14.1) …. 14print int(14.6) …. 14print int(-14.1) …. –15print int(-14.6) …. –15
print cint(14.1) …. 14print cint(14.6) …. 15print cint(-14.1) …. –14print cint(-14.6) …. –15
print fix(14.1) …. 14print fix(14.6) …. 14print fix(-14.1) …. –14print fix(-14.6) …. –14
2. Sgn Functionif number is Sgn function returnsgreater than 0 1equal to 0 0less than 0 -1
print sgn(-5) …. -1print sgn(0) …. 0print sgn(10) …. 1x = sgn (-5)print x …. -1
3. Val( ) Functionprint 2+5 …. 7print “2” + ”5” …. 25print val(“2”) + val(“5”) …. 7 print val(“18th Road”) …. 18
4. Rnd FunctionText1.text = rnd(1)
Or print rnd(3)To produce a random number within the given range.int ((upperbound – lowerbound + 1) * rnd + lowerbound)
Example:(To produce a random number between 1 and 6)dim x as integer
x = int ((6 – 1 + 1) * rnd + 1)Or x = int (( 6 * rnd) + 1)
Date and Time Functions1. Now( ) Function
print now( )Or print now .… 1/17/06 11:25:50 AM
2. Date and Date$ FunctionsPrint date …. 1/17/04Print date$ …. 01-17-2004
Date Date$- Variant String- Uses ”/” Uses “-“- Do not places 0 Places 0- Do not appends 19 or 20 Appends 19 or 20
before year before year
3. Time and Time$ FunctionsPrint time …. 9:11:50 PMPrint time$ …. 21:11:50
Time Time$- Variant String- 12 hour 24 hour4. Datepart FunctionSyntax:
Datepart (interval, validdate)Intervalyyyy yearq quarterm monthy day of the yeard dayw weekdayww weekh hourn minutes second
Example:dim x as datex = #1/17/2006#Print datepart (“m”, x) - 1Print datepart(“yyyy”, now) - 2006
5. Day, Month and Year Functions
Print day(date) - 17Print month (date) - 1Print year(date) - 2006dim x as datex = #1/19/2006#print year(x) - 2006 print day(x) - 19
6. Hour, Minute and Second Functionsdim x as datex = #12:10:41 AM#Print hour(x) - 12Print minute(x) - 10Print second(x) - 41Print minute(now)
7. Timer( ) FunctionPrint timer
Or Text1.text = timer( )
8. Dateadd and Datediff FunctionsSyntax:
Dateadd (interval, number, olddate)Example:
x = dateadd(“y”, 25, now)Or x = dateadd(“yyyy”, 3, now)
Datediff FunctionSyntax: Datediff(interval, date1, date2)Example:
x = #1/17/2006#y = #2/25/2004#n = datediff (“yyyy”, x, y)print n …. 2
Miscellaneous Functions1. Isdate( ) Function
dim x as integer, y as stringx = 10y = “12/17/2005”print isdate(x) .… falseprint isdate(y) .… true
2. Isnumeric( ) Functionprint isnumeric(x) …. trueprint isnumeric(y) …. false
3. Isempty( ) Function4. Isnull( ) Function
5. Vartype( ) FunctionExample:
dim x as integer, y as stringPrint vartype (x) …. 2Print vartype (y) …. 8
6. Inputbox( ) FunctionSyntax:
Inputbox (prompt [,title] [,default] [,xpos] [,ypos]…)Example:
p = inputbox(“Enter the number“, “My Project”, 10, 100, 200)
7. Msgbox( ) FunctionSyntax:
Msgbox (prompt [,buttons] [,title])Example:
Msgbox (“A Trial Message“)x = Msgbox (“Do you wish to continue:“, 4 + 32, “My Project”)
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