Question

Back in VB6, you were able to re-assign a string’s value to itself plus other string values, such as:

str_Duplications_Line = str_Duplications_Line & pRow_Prime.Value(i_FieldNum)

Now, intellisense is not picking it up as an error, nor is the compiler complaining, but when it is ran, it bombs out on that line, and other multiple line such as these:

str_Duplications_Line = str_Duplications_Line & ","

str_Duplications_AllFields = str_Duplications_AllFields + str_Duplications_Line + vbCrLf

Any idea why this is happening, and how I can fix this? Or at least, simulate the same thing in VB.NET?

Answer 1

Here is the diference between & and +

"abc" + "def" = "abcdef"
"abc" & "def" = "abcdef"
"111" + "222" = "111222"
"111" & "222" = "111222"
"111" & 222 = "111222"
"111" + 222 = 333
"abc" + 222 = conversion error

If any one operand is null, you may get an error.