ASP Procedures

ASP Procedures
ASP Procedures

ASP Procedures : In ASP you can call a JavaScript procedure from a VBScript and vice versa.

Procedures

The ASP source code can contain procedures and functions:

Example

<!DOCTYPE html>
<html>
<head>
<%
sub vbproc(num1,num2)
response.write(num1*num2)
end sub
%>
</head>
<body>

<p>Result: <%call vbproc(3,4)%></p>

</body>
</html>

Output

You can call a procedure like this:

Result: 12

Or, like this:

Result: 12

  • Insert the <%@ language=”language” %> line above the <html> tag to write the procedure/function in another scripting language:

Example

<%@ language=”javascript” %>
<!DOCTYPE html>
<html>
<head>
<%
function jsproc(num1,num2)
{
Response.Write(num1*num2)
}
%>
</head>
<body>

<p>Result: <%jsproc(3,4)%></p>

</body>
</html>

Output

Result: 12

Differences Between VBScript and JavaScript

  • When calling a VBScript or a JavaScript procedure from an ASP file written in VBScript, you can use the “call” keyword followed by the procedure name. If a procedure requires parameters, the parameter list must be enclosed in parentheses when using the “call” keyword. If you omit the “call” keyword, the parameter list must not be enclosed in parentheses. If the procedure has no parameters, the parentheses are optional.
  • When calling a JavaScript or a VBScript procedure from an ASP file written in JavaScript, always use parentheses after the procedure name.

VBScript Procedures

VBScript has two kinds procedures:

  • Sub procedure
  • Function procedure

VBScript Sub Procedures

A Sub procedure:

  • It is a series of statements, enclosed by the Sub and End Sub statements
  • It can perform actions, but does not return a value
  • It can take arguments

Sub mysub()
  some statements
End Sub

or

Sub mysub(argument1,argument2)
  some statements
End Sub

Example

Sub mysub()
response.write(“I was written by a sub procedure”)
End Sub

Output

I was written by the script
I was written by a sub procedure

VBScript Function Procedures

A Function procedure:

  • It is a series of statements, enclosed by the Function and End Function statements
  • It can perform actions and can return a value
  • It can take arguments that are passed to it by a calling procedure
  • It can perform without arguments, must include an empty set of parentheses ()
  • It returns a value by assigning a value to its name

Function myfunction()
some statements
myfunction=some value
End Function

or

Function myfunction(argument1,argument2)
some statements
myfunction=some value
End Function

Example

function myfunction()
myfunction=Date()
end function

Output

Today’s date: 10/28/2017

A Function procedure can return a result.

Calling a Procedure

This simple function procedures is called to calculate the sum of two arguments:

Example

Function myfunction(a,b)
myfunction=a+b
End Function

response.write(myfunction(5,9))

Output

14

  • The function “myfunction” will return the sum of argument “a” and argument “b”. In this case 14.
  • When you call a procedure you can use the Call statement, like this:

Call MyProc(argument)

Or, you can omit the Call statement, like this:

MyProc argument

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