如何使用regex或linq替换c＃中的特定字符串

Question

I have a string where I need to replace a particular string, my string is as follows

string s = @"-Username ABC **-Password XYZ** -Address MNO";
string[] s1 = s.Split('-');
var newList = s1.Where(s2 =>s2.Contains("Password"));

I need to replace the string -Password XYZ to -Password **** can some one help me

Answer 1

Test

    [TestCase("-Username ABC -Password XYZ -Address MNO", "-Username ABC -Password *** -Address MNO")]
    [TestCase("-Username ABC -Password XYZ", "-Username ABC -Password ***")]
    public void Test(string toTest, string expected ) 
    {
        Assert.AreEqual(expected, DestroyPassword(toTest));
    }

Code

    public static string DestroyPassword(string str )
    {
          var r = new Regex("-Password .*?($| )");//? in .net means not greedy
          return r.Replace(str, "-Password ***$1");
    }

EDIT:

Word of caution

This doesn't mask passwords with spaces in them. If you know that -Address is always the next token then something like this will be better:

    public static string DestroyPassword(string str )
    {
        var r = new Regex("-Password .*?($| -Address)");//? in .net means not greedy
        return r.Replace(str, "-Password ***$1");
    }

but event that doesn't deal well with the case when the password contains '-Address'

Answer 2

You can use Regex.Replace(input, replacement). Function will replace all values found by regex expression.

string input = @"-Username ABC **-Password XYZ** -Address MNO";
string pattern = "(-Password )(\S+)";
string replacement = "$1****";
Regex regex = new Regex(pattern);
string result = regex.Replace(input, replacement);