Conditional statements in vb script
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VBScript provides two main types of conditional statements for controlling program flow: the If...Then statement and Select Case statement. The If...Then statement allows executing different blocks of code based on conditional checks, and can include ElseIf and Else clauses. The Select Case statement chooses between multiple blocks of code based on the value of an expression. VBScript also supports looping structures like For...Next, Do...Loop, and While...Wend to repeat blocks of code. These conditional and looping statements allow inserting verification points and error handling in scripts.
![Dim num1, num2, operation
num1=5
num2=10
operation= Lcase(InputBox ("Enter an operation"))
Select Case operation
Case "add"
msgbox "res:" &(num1+num2)
Case "sub"
msgbox "res:" &(num1-num2)
Case "div"
msgbox "res:" &(num2/num1)
Case Else
msgbox "res:" &(num1*num2)
End Select
Using Control Structures to Make Code Repeat
For…Next
The first structure is often referred to as the For…Next loop. The syntax for this structure is
For counter = start to finish [Step step]
...code that gets repeated
Next
Example:
' increment loop by 2
Counter = 1
Result = 0
For Counter = 1 to 5 step 2
Result=Result + Counter
msgbox Result
Next](https://image.slidesharecdn.com/conditionalstatementsinvbscript-141029071528-conversion-gate01/85/Conditional-statements-in-vb-script-3-320.jpg)
Conditional statements in vb script
- 1. Control Flow Functions In VbScript Conditional statements allows us to make decisions and to control the flow of execution of a script or one of its sections and accordingly repeat actions. Usage of VBScript Conditional statements in QTP: I) We use conditional statements to insert verification points. II) We can user conditional checks for error handling purpose also. VBScript mainly provides following 2 types of decision making statements : I) If ...Then Statement. II) Select Case Statement. Simple If ( Single line without block) statement is Condition is True: Dim myDate myDate=#10/10/2014# if myDate < date then myDate =date+2 ' where current date is 10/13/2014 msgbox myDate 'O/P - 10/15/2014 Execute block of statements using Simple If Dim myDate myDate=#10/10/2014# if myDate < date then myDate =date+2 ' where current date is 10/13/2014 msgbox myDate msgbox "Mindfire solutions" End If 'O/P - 10/15/2014 Mindfire solutions IF ...Then...Else Dim a,b a=5 b=20
- 2. If a > b Then Msgbox "a is Greater" Else msgbox "b is Greater" End If If...Then...ElseIf..Else Statement Dim a a = -5 If a > 0 Then Msgbox "a is a POSITIVE Number" ElseIf a < 0 Then Msgbox "a is a NEGATIVE Number" Else Msgbox "a is EQUAL than ZERO" End If nested if statements Dim a a = 23 If a > 0 Then Msgbox "The Number is a POSITIVE Number" If a = 1 Then Msgbox "The Number is Neither Prime NOR Composite" Elseif a = 2 Then Msgbox "The Number is the Only Even Prime Number" Elseif a = 3 Then Msgbox "The Number is the Least Odd Prime Number" Else Msgbox "The Number is NOT 0,1,2 or 3" End If ElseIf a < 0 Then Msgbox "The Number is a NEGATIVE Number" Else Msgbox "The Number is ZERO" End If 'O/P - The Number is a POSITIVE Number The Number is NOT 0,1,2 or 3 Select Case statement Executes one of several groups of statements, depending on the value of an expression.
- 3. Dim num1, num2, operation num1=5 num2=10 operation= Lcase(InputBox ("Enter an operation")) Select Case operation Case "add" msgbox "res:" &(num1+num2) Case "sub" msgbox "res:" &(num1-num2) Case "div" msgbox "res:" &(num2/num1) Case Else msgbox "res:" &(num1*num2) End Select Using Control Structures to Make Code Repeat For…Next The first structure is often referred to as the For…Next loop. The syntax for this structure is For counter = start to finish [Step step] ...code that gets repeated Next Example: ' increment loop by 2 Counter = 1 Result = 0 For Counter = 1 to 5 step 2 Result=Result + Counter msgbox Result Next
- 4. 'Example with Exit For For Counter=1 to 5 If Counter=3 Then Exit for End If msgbox Counter Next Do…Loop The first loop structure you can use is the Do While… Loop structure. The basic syntax for this structure is Do While <Condition> ….Code with in the loop for repetitive activity Loop Example: Counter = 1 Do While Counter < 4 Total =Inputbox("Please enter the total marks in numbers") If Total < 30 Then MsgBox "Fail" ElseIf Total >=30 and Total <=100 then Msgbox "Pass" Else Msgbox "Invalid Marks" End If
- 5. Counter = Counter + 1 Loop Exit Do While loop: i = 0 Do While i <= 100 If i > 10 Then Exit Do ' Loop Exits if i>10 End If msgbox("The Value of i is : " &i) i = i + 2 Loop There is an another piece of DO ..Loop. Below is the syntax: Do ….Code with in the loop for repetitive activity Loop Until condition Example: Counter = 1 Do Total =Inputbox("Please enter the total marks in numbers") If Total < 30 Then MsgBox "Fail" ElseIf Total >=30 and Total <=100 then Msgbox "Pass" Else Msgbox "Invalid Marks" End If Counter = Counter + 1
- 6. Loop until Counter > 4 Exit Do Until loop: i = 0 Do i = i + 2 If i > 10 Then Exit Do ' Loop Exits if i>10 End If msgbox("The Value of i is : " &i) Loop Until i > 100 For Each...Next statement - runs code for each item in a collection or each element of an array Example: Dim birds(2) birds(0)="parrot" birds(1)="Crow" birds(2)="Sparrow" For Each x In birds msgbox(x) Next While...Wend: Executes a series of statements as long as a given condition is True. Example: Dim Counter Counter = 0 ' Initialize variable. While Counter < 20 ' Test value of Counter. Counter = Counter + 1 ' Increment Counter. msgbox Counter Wend ' End While loop when Counter > 19.