VBS : Tutorial 1 (variables and datatypes)

VBS : Tutorial 1 (variables and datatypes)

 

Input/ Output Operations

Displays a prompt in a dialog box, waits for the user to input text or click a button, and returns the contents of the text box.

Example:

Dim Input

Input = InputBox("Enter your name")

MsgBox ("You entered: " & Input))

 

 

Variable

o Must begin with an alphabetic character.

o Cannot contain period.

o Must not exceed 255 characters.

o Must be unique

Ex:          dim variable_name

                variable_name =InputBox("Enter your name:")

 

A variable containing a single value is a scalar variable.

A variable containing a series of values, is called an array variable.

 

 

VB Script Data Types--VARIANT

1.       One data type called a VARIANT

2.       Special kind of data type

3.       It can contain different kinds of information, depending on how it is used

4.       Only data type in VBScript

5.       Variant behaves in a way that is most appropriate for the data it contains.

6.       VarType

 

 

-------------------------------VarType ----------------------------------

Example 1 :

Dim a

a="hi"

msgbox vartype(a)

 

Example 2 :

Dim a

a="3"

msgbox vartype(a)

 

 

·         0 = vbEmpty - Indicates Empty (uninitialized)

·         1 = vbNull - Indicates Null (no valid data)

·         2 = vbInteger - Indicates an integer

·         3 = vbLong - Indicates a long integer

·         4 = vbSingle - Indicates a single-precision floating-point number

·         5 = vbDouble - Indicates a double-precision floating-point number

·         6 = vbCurrency - Indicates a currency

·         7 = vbDate - Indicates a date

Example1:

                        Dim a

                        a="1/1/2013"

                        msgbox vartype(a)

                        a=cdate(a)

                        msgbox vartype(a)

Example2:

                        Dim a

                        a="10:55:05"

                        msgbox vartype(a)

                        a=cdate(a)

                        msgbox vartype(a)

 

·         8 = vbString - Indicates a string

·         9 = vbObject - Indicates an automation object

·         10 = vbError - Indicates an error

·         11 = vbBoolean - Indicates a boolean

·         12 = vbVariant - Indicates a variant (used only with arrays of Variants)

·         13 = vbDataObject - Indicates a data-access object

·         17 = vbByte - Indicates a byte

·         8192 = vbArray - Indicates an array

--------------------------------------------------------------------------------------------

 

Keywords -

Date-                    Returns the current date

Time-                    Returns the current time 

Example : msgbox Time

 

Day -                      Returns day from a date

Month -              Returns month from a date

Weekday -          Returns weekday from a date

Year -                    Returns year from a date

Hour -                   Returns hour from a time

Minute-               Returns minute from a time

Second-               Returns seconds from a time

Example : msgbox Year(Date)

                msgbox second(time)

 

Now-                    Returns current date and time

Example : msgbox Now

 

Abs                        Returns absolute value of a number

Asc                         Returns the ASCII code of a character

Chr                         Returns a character from an ASCII code

msgbox abs(-1.3)

msgbox asc("a")

 

CBool                   Converts a variant to a boolean

CByte                    Converts a variant to a byte

msgbox CByte(123.33) > 123

CDate                    Converts a variant to a date

CDbl                      Converts a variant to a double

Cint                       Converts a variant to an integer

CLng                      Converts a variant to a long

CSng                      Converts a variant to a single

CStr                        Converts a variant to a string

--------------------------------------------------------------------------------

Constant

Example :

Dim a

                a="hi"

                const x="xxx"

                msgbox x

                x=10

----------------------------------------------------------------------------------

Operators

1.       Parentheses to override override the order of precedence

 

                Operator                                                                             Description

1) Exponentiation Operator (^)                 Raises a number to the power of an exponent.

2) Multiplication Operator (*)                     Multiplies two numbers.

3) Division Operator (/)                                 Divides two numbers and returns a floating-point result.

4) Integer Division Operator (\)                 Divides two numbers and returns an integer result.

5) Mod Operator                                              Divides two numbers and returns only the remainder.

6) Addition Operator (+)                               Sums two numbers.

7) Subtraction Operator (-)                          Finds the difference between two numbers or indicates the negative value of a numeric expression.

8) Concatenation Operator (&)                  Forces string concatenation of two expressions.

 

Operator

1) =        Equal to                5) <=      Less than or equal to

2) <>      Not equal to       6) >=      Greater than or equal to

3) <        Less than             7) Is        Object equivalence

4) >        Greater than                     

 

Operator                                                             Description

1) Addition Operator (+)                               Sums two numbers.

1.       1) Both expressions are numeric-       Add.

2.       2) Both expressions are strings-         Concatenate.

3.       3) One expression is numeric and the other is a string   -Add.

 

2) Concatenation Operator (&)  --->        Forces string concatenation of two expressions.

 

Operator                                             Description

               

1) Not-                  Performs logical negation on an expression.       

result= Not expression

 

2) And-                 Performs a logical conjunction on two expressions.

result= expression1 And expression2

 

3) Or      -             Performs a logical disjunction on two expressions.

                result= expression1 Or expression2

 

4) Xor    -              Performs a logical exclusion on two expressions.             

result= expression1 Xor expression2

 

5) Eqv                    -Performs a logical equivalence on two expressions.

result= expression1 Eqv expression2

                                                                                                (Ex-OR is given as "either A OR B but NOT both)