Scripting Solutions with WSH and COM: Trapping and Handling Errors in Your Scripts

This month, I concentrate on a subject that often doesn't receive generic coverage: how you can trap and handle errors in VBScript code that you write for the Windows Script Host (WSH) environment. I discuss three practical ways you can trap and handle errors: explicitly declaring variables, basic error handling with the CheckError subprocedure, and advanced error handling with customized CheckError subprocedures.

Explicitly Declaring Variables
In VBScript, you don't have to explicitly declare the variables that you use. However, explicitly declaring variables is good practice. To make sure that you explicitly declare variables, you can use the Option Explicit command at the beginning of your script. Option Explicit forces the VBScript interpreter (in this case, WSH) to make sure that you use an explicit declaration (i.e., a Dim, Public, or Private statement) to declare a variable before you use it. If you explicitly declare variables and use Option Explicit, you'll spend less time debugging scripts because you'll immediately catch such errors as misspelled variable names and mismatched variables. . . .