What
is a Function?
- A function is a group of reusable code which can be called anywhere in your program.
- eliminates the need of writing same code over and over again.
- enable programmers to divide a big program into a number of small and manageable functions.
- Apart from inbuilt Functions, VBScript allows us to write user-defined functions l.
- There two types of procedures used for VBScript:
2. Function procedures -a set of instructions that returns a value as output.
A Function procedure:
- is a series of statements, enclosed by the Function
and End Function statements
- can perform actions and can return a value
- can take arguments that are passed to it by a
calling procedure
- without arguments, must include an empty set of
parentheses ()
- returns a value by assigning a value to its name
Function Definition :
<html>
<body>
<script language="vbscript" type="text/vbscript">
Function Functionname(parameter-list)
statement 1
statement 2
statement 3
.......
statement n
End Function
</script>
</body>
</html>
Example
:
<html>
<body>
<script language="vbscript" type="text/vbscript">
Function tellHello()
msgbox("Hello ")
End Function
</script>
</body>
</html>
Calling a function
To execute a function, just call it by writing its name
(case sensitive) followed by an open parenthesis (and possibly arguments) and
then a closing parenthesis:
Syntax:
Syntax:
Functionname()
OR
Call Functionname()
Example:
<html>
<body>
<script language="vbscript" type="text/vbscript">
Function tellHello()
msgbox("Hello ")
End Function
Call tellHello()
</script>
</body>
</html>
Returning a Value from a Function :
- A Vb Script function can have an optional return statement. This is required if you want to return a value from a function.
- The Function procedure can return a value of the Variant
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