Error Handling in VBScript
Error handling is the way for responding to occurrence of some unexpected situation that arrives during the computation. In automation testing, these unexpected situation can be like objects of application getting changed or some mathematical manipulation etc.
For handling such situation Visual Basic Script Edition (VBScript) provides us some of the methods. The details and usage of these methods are as follows:
On error resume next
This statement specifies that when any run time error occurs at particular line in script the control goes to the next line following the statement where the error as occurred.
For example: We are performing a division by zero, and if such situation occurs we dont want script to be interrupted. So we will be adding “On error resume next” statement at the top of the script.
On error resume next
If Div=0 then
On error go to 0
Disables any enabled error handler and reset it to nothing
Err object is the intrinsic object with global scope means there is no need to create the instance of it for accessing the various methods of it.The details of all the methods of err object can be find in the below table:
|Number||Returns the integer value telling the type of the error occurred|
|Description||Gives the reason for the occurrence of the error|
|Clear||Helps to reset the error handler to nothing once the error has been handled.|
Lets take the example of division by zero again.
'Call the division function
on error resume next
'divide by zero
' Report the error occured. You can see the error number and description in msgbox
If Err.number <> 0 then
Msgbox “Error Number” + Err.Number
Msgbox “Error Description” + Err.Description
'disables error handling
on error goto 0
In Visual Basic, we have two more methods available for error handling
On Error Goto Line – Moves the control to a particular line number.
On Error Goto Label – Moves the control to a particular section of code which is defined in a label.
These two methods are not available in VBScript.