I've been tasked with an ExactTarget task, which uses Ampscript. Trying to learn on the go here. See code snippet below:
%%[
Var @testString, @testOutput
Set @testString = Qwerty
Set @testOutput = BuildRowsetFromString(@testString,"~")
]%%
TestOutput:%%= v(@testOutput) =%%
The code works if the testString contains a ~, but when there is no ~ character in the string, the ouput is blank. Is this correct by design? Do I need to add a conditional to check for the presence of the ~ character?
That's the expected behavior. The BuildRowsetFromString() function alone isn't going to return any value when displayed, you're going to need to use Row() and Field() in order to pull the value out.
Using your example:
%%[
Var @testString, @testOutput
Set @testString = "Qwerty"
Set @testOutput = BuildRowsetFromString(@testString,"~")
]%%
RowCount: %%=RowCount(@testOutput)=%%
TestOutput: %%=v(@testOutput)=%%
The RowCount() function returns a value of 1, essentially saying it knows there's at least one 'row' in there. To display that one value, you'll need to wrap that value with Field() and Row():
TestOutput: %%=Field(Row(@testOutput,1),1)=%%
If you want to display other values in the string, say you were passing "Qwerty~Second~Third", you'll need to either change the number at the Row() function or perform a loop.
References