string.replace无法正常工作

Question

I have function which accepts string (which is basically a XML doc). I am making this change:

  if (filterXml.Contains("&"))
    {
        filterXml.Replace("&", "&");
    }

It is hitting this condition but not replacing the

 & to &

What is wrong here?

Answer 1

Remember, strings are immutable. So you have to assign the return value of the Replace method (notice that it returns a String object) back to your variable.

  if (filterXml.Contains("&"))
  {
      filterXml = filterXml.Replace("&", "&");
  }

If you're doing a lot of work with String objects, make sure to read the the String reference page

Answer 2

You need to save the result:

filterXml = filterXml.Replace("&", "&");

but I would recommend encoding ALL special XML characters.

Answer 3

You don't even need to do the Contains check. Just do the following:

filterXml = filterXml.Replace("&", "&");

If there aren't any ampersands in the string, then nothing will change.

Answer 4

Try -

  if (filterXml.Contains("&"))
    {
        filterXml = filterXml.Replace("&", "&");
    }

Strings are immutable in .net, so the replace function returns a new string rather than altering the string it is called on. You are able to assign the altered result to the variable that contained your original string value.

Answer 5

  if (filterXml.Contains("&"))
    {
        filterXml = filterXml.Replace("&", "&");
    }