How can I replace a dictionary item name with its value in vb.net string?

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Hi guys,
I have a string and a dictionary. Basically I want to iterate through all the items in the dictionary, if it finds a match in the string, it replaces that match with the dictionaryitem's name with its value in the string. I have this code:

VB

Dim writArg As String = Arguments(0)
                For Each DictItem In DeclaredVariables
                    MsgBox(DictItem.Key)
                    writArg = writArg.Replace(DictItem.Key, DictItem.Value)
                Next
                Return writArg

Where, declaredvariables hosts the variable names and values. But it won't work. It will not replace it. Can someone help?
Thanks,
-iProgramIt

EDIT:
This is the code for adding in the dictionary key. It doesn't seem to save.

VB

DeclaredVariables.Add(Arguments(0), Arguments(1))

Posted 2-Oct-15 1:57am

iProgramIt

Updated 2-Oct-15 3:02am

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OriginalGriff · Answer 1 · 2015-10-02T02:26:00

Solution 2

Replace is case sensitive - so check that your argument string contains exactly the same text as the string you are comparing "Hello World!" will not match "world", or "World ".

I'd start with the debugger and look at exactly what you are trying to replace each time, and exactly what you are trying to replace it in.

It might be worth adding a check for writArg.Contains(DictItem.Key) and breaking if it finds a match. If it doesn't break...it doesn't match!

Posted 2-Oct-15 2:26am

OriginalGriff

Comments

iProgramIt 2-Oct-15 8:59am

Tried that. It said the dictionary contained nothing after adding a key.. that the length/count was 0.

iProgramIt 2-Oct-15 8:59am

The length/count = 0. Made an edit ^

Maciej Los 2-Oct-15 11:08am

Using Contains method is quite good idea. +4!
But i suggest alternative solution, please see.

OriginalGriff 2-Oct-15 11:18am

Except two things:
1) I don't like relying on try...catch for "normal" processing - I would prefer to use Dictionary.Contains instead.
2) Your code doesn't do what his does - if the input string is "hello there what is happening?" his code would produce "hello there 123t is happening?" from your inputs. Yours would print an error message.

I suspect this is a "parameter substitution" thing, like replacing [NAME] with "Maciej Los" in a form letter.

Maciej Los 2-Oct-15 15:44pm

It's not a matter of "liking". I really do understand that you prefer to use Contains instead of Try... End Try. I'd say: No matter of method, it's a matter of result ;)
As per my understanding OP wants to replace the name of variable with its value. So, my code does exactly what OP wants to achieve.

Thank you for your comment, Paul.

Cheers, Maciej

OriginalGriff 2-Oct-15 16:42pm

You misunderstand me! :laugh:
Your code only replaces if the whole input string matches the key value, the OP code uses Replace which changes substrings within the input string.

Maciej Los 2-Oct-15 18:24pm

I understand you well. I think it's OP requirements...

Maciej Los · Answer 2 · 2015-10-02T05:06:00

The simplest way is:

VB

Dim DeclaredVariables As Dictionary(Of String, String) = New Dictionary(Of String, String)

DeclaredVariables.Add("wah","123")
DeclaredVariables.Add("wha","132")
DeclaredVariables.Add("awh","213")
DeclaredVariables.Add("ahw","231")
DeclaredVariables.Add("haw","321")
DeclaredVariables.Add("hwa","312")

Dim writArg As String = "wha"
writArg = DeclaredVariables(writArg)

But i need to warn you: this may cause KeyNotFoundException[^], so you should avoid this by using Try... Catch... End Try statement[^]:

VB

Try
    writArg = DeclaredVariables(writArg)
Catch ex As KeyNotFoundException
    Console.WriteLine("{0}", ex.Message)
End Try