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[waveterm]

I get an Index Out Of Range error with the GetToken method. I can't understand what's going on here. Anyone work this out? I'll attach a sample of the code if someone will tell me how. Thanks

[CodeMorphis]

Can you please send your example to support@codemorphis.com? We'll investigate the problem.

Thanks,

CodeMorphis Support

[waveterm]

sent

[CodeMorphis]

Hi waveterm,

Thanks for sending in your example program.

The problem is not a bug but rather a misusage or programming error. The error message that you see is provided by Synopsis to help you identify the programming error.

Let’s look at your program:



In data port 0 of the String Tokenizer component named “Str Tok 1” you have supplied the input string to tokenize: “a:b:c:d” along with a separator character “:”. This means that you should have 4 tokens split by the component. So the input string “a:b:c:d” is stored in “Str Tok 1”.

The problem is that you are then using a new String Tokenizer component named “Str Tok 2” to try to retrieve the split tokens. This second component does not contain your input string and hence neither your expected tokens and so when you ask it for the Nth token in your For Loop, it will of course complain that the index is out of bounds since it has 0 tokens.

What you need to do is query “Str Tok 1”, which contains your input string. Note that the String Tokenizer component is an object component, as indicated by the green background. This means that the component maintains its own data in addition to providing one or more services. You can read about object components in the Help module, in Getting Started | Synopsis Components | Object Connections.

The way to interact with an object component and get to its data is via the Service Call component:


Note that we have replaced the component “Str Tok 2” with a Service Call component that refers to the first String Tokenizer component.

This now does what you want – you are passing the token index from the For Loop control into the Service Call component that acts as an interface to the “Str Tok 1” component.

You can download the corrected version of the program here:
http://www.codemorphis.com/articles/ans08/ans_022808/TokenIndex_Corrected.vpd

As an additional note, you have the number of tokens “hard-coded” into data port 1 of the For Loop component, meaning that you edited the port and put the value 4 there. This works fine for the input of your String Tokenized component “a:b:c:d” which has 4 tokens separated by the colon character. But if you were to change the input string to say “a:b:c:d:e” then you would have 5 tokens but your For Loop component still only loops 4 times. A better programming style would be to pass the output of the “Split String” service of the String Tokenizer component to the For Loop:


This way, your program will behave correctly when you change the input string.

Hope that this helps.

[waveterm]

[CodeMorphis]

waveterm,

[waveterm]

[CodeMorphis]