Replacing bad characters of a String with bad characters

Question

I just wondered what\'s the easiest way to replace a string characters that must be replaced subsequently.

For example:

var str = \"[Hello World]\";         


        

Answer 1

What about this elegant regular expression approach:

Regex.Replace("[Hello World]", @"[\[\]]", "[$0]");

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Unit test it?

[TestMethod]
public void UnitTestThat()
{
    Assert.AreEqual(@"[[]Hello World[]]", Regex.Replace("[Hello World]", @"[\[\]]", "[$0]"));
}

Test passed

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Edit @JohnMcGrant

Here is a slightly less inefficient version of your code, which has, by the way, exactly the same behaviour as the above regex:

string result = input.Aggregate(new StringBuilder(), (a, c) =>
    -1 != "[]".IndexOf(c) ? a.AppendFormat("[{0}]", c) : a.Append(c)).ToString();