String manipulation with & or + in VB.NET

by

The + and & operators are not identical in VB.NET.

Using the & operator indicates your intention to concatenate strings, while the + operator indicates your intention to add numbers. Using the & operator will convert both sides of the operation into strings. When you have mixed types (one side of the expression is a string, the other is a number), your usage of the operator will determine the result.

1 + "2" = 3 'This will cause a compiler error if Option Strict is on'
1 & "2" = "12"
1 & 2 = "12"
"text" + 2 'Throws an InvalidCastException since "text" cannot be converted to a Double'

So, my guideline (aside from avoiding mixing types like that) is to use the & when concatenating strings, just to make sure your intentions are clear to the compiler, and avoid impossible-to-find bugs involving using the + operator to concatenate.

More Related Contents:

  1. How do you get a string from a MemoryStream?
  2. What do Option Strict and Option Explicit do?
  3. Clean up Excel Interop Objects with IDisposable
  4. Reference variables and objects elsewhere in a form
  5. String.Join vs. StringBuilder: which is faster?
  6. Parse Delimited CSV in .NET
  7. Is the Microsoft.VisualBasic namespace “true .NET” code?
  8. Which is generally best to use — StringComparison.OrdinalIgnoreCase or StringComparison.InvariantCultureIgnoreCase?
  9. Is String a primitive type?
  10. Regex.IsMatch vs string.Contains
  11. BitmapImage in WPF does lock file
  12. Does this code prevent SQL injection?
  13. Option Strict On and .NET for VB6 programmers
  14. Deserialize using JSON.net
  15. Cause this VB6-like smell, which VB.NET allows, to error instead: WinFormType.InstanceProp=Value [DISABLE My.Forms]
  16. String.Format – how it works and how to implement custom formatstrings
  17. How to print datagridview table with its header in vb.net?
  18. How to draw a signature and save it to disc as a Bitmap?
  19. How to convert date format in vb.net?
  20. Redirect Trace output to Console
  21. How to make a Windows Forms .NET application display as tray icon?
  22. LinqToSql declare and instantiate DataContext best practice?
  23. Assigning a value to ComboBox Items
  24. Should I always use the AndAlso and OrElse operators?
  25. Is there a way to define an implicit conversion operator in VB.NET?
  26. Custom button captions in .NET messagebox?
  27. .NET — Textbox control – wait till user is done typing
  28. How to post a file via HTTP post in vb.net
  29. How to securely store a connection string in a WinForms application?
  30. VB.NET Excel Program Leaves EXCEL.EXE floating after completion

Leave a Comment