How to delete the duplication part in a string

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A

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I have a string like

string myString="dog,cat,dog,tiger"
I want to delete the duplication part, and make myString to "dog,cat,tiger"

How can I do that?
 
ad,

First, you need to create a hashtable (or dictionary, I'll use a
hashtable since I don't know if you have access to .NET 1.1).

// Create the hashtable. If you want case-insensitivity, then you have to
use
// an overload of the constructor that takes the appropriate
case-insensitive
// comparer.
Hashtable parts = new Hashtable()

// Cycle through the parts.
foreach (string part in myString.Split(new char[1]{','}))
{
// If the part exists in the hashtable, don't add it.
if (!parts.ContainsKey(part))
{
// Add the part.
parts.Add(part, true);
}
}

// Now cycle through the parts and re-create the string.
// The builder for the new string.
StringBuilder builder = new StringBuilder();

// Cycle through the keys.
foreach (string key in parts.Keys)
{
// Append to the string builder.
parts.AddFormat("{0},", key);
}

// Remove the last comma.
if (parts.Count > 0) then
{
// Remove the last comma.
parts.Remove(builder.Length - 1, 1);
}

// The string.
myString = builder.ToString();

I didn't run this, so make sure you test it first.

Hope this helps.
 
Thanks,
You do me a great favor!


Nicholas Paldino said:
ad,

First, you need to create a hashtable (or dictionary, I'll use a
hashtable since I don't know if you have access to .NET 1.1).

// Create the hashtable. If you want case-insensitivity, then you have to
use
// an overload of the constructor that takes the appropriate
case-insensitive
// comparer.
Hashtable parts = new Hashtable()

// Cycle through the parts.
foreach (string part in myString.Split(new char[1]{','}))
{
// If the part exists in the hashtable, don't add it.
if (!parts.ContainsKey(part))
{
// Add the part.
parts.Add(part, true);
}
}

// Now cycle through the parts and re-create the string.
// The builder for the new string.
StringBuilder builder = new StringBuilder();

// Cycle through the keys.
foreach (string key in parts.Keys)
{
// Append to the string builder.
parts.AddFormat("{0},", key);
}

// Remove the last comma.
if (parts.Count > 0) then
{
// Remove the last comma.
parts.Remove(builder.Length - 1, 1);
}

// The string.
myString = builder.ToString();

I didn't run this, so make sure you test it first.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

ad said:
I have a string like

string myString="dog,cat,dog,tiger"
I want to delete the duplication part, and make myString to
"dog,cat,tiger"

How can I do that?
Click to expand...
Click to expand...
 
That's a lot of code for what I presumed InStr and Replace methods could do
in a couple of lines of code.
Any comments about my sugesstion Nicholas?

<%= Clinton Gallagher

Nicholas Paldino said:
ad,

First, you need to create a hashtable (or dictionary, I'll use a
hashtable since I don't know if you have access to .NET 1.1).

// Create the hashtable. If you want case-insensitivity, then you have to
use
// an overload of the constructor that takes the appropriate
case-insensitive
// comparer.
Hashtable parts = new Hashtable()

// Cycle through the parts.
foreach (string part in myString.Split(new char[1]{','}))
{
// If the part exists in the hashtable, don't add it.
if (!parts.ContainsKey(part))
{
// Add the part.
parts.Add(part, true);
}
}

// Now cycle through the parts and re-create the string.
// The builder for the new string.
StringBuilder builder = new StringBuilder();

// Cycle through the keys.
foreach (string key in parts.Keys)
{
// Append to the string builder.
parts.AddFormat("{0},", key);
}

// Remove the last comma.
if (parts.Count > 0) then
{
// Remove the last comma.
parts.Remove(builder.Length - 1, 1);
}

// The string.
myString = builder.ToString();

I didn't run this, so make sure you test it first.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

ad said:
I have a string like

string myString="dog,cat,dog,tiger"
I want to delete the duplication part, and make myString to
"dog,cat,tiger"

How can I do that?
Click to expand...
Click to expand...
 
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