Question

I am trying to replace string but due to few matching words it is replacing both the string.

Val1 = "CASE WHEN [" + isParent + "] = 0 THEN 'False' WHEN [" + isParent + "] = 1 THEN 'True' END ";
Val2 = "CASE WHEN [" + isChild + "] = 0 THEN 'False' WHEN [" + isChild  + "] = 1 THEN 'True' END ";
val3 = str.Replace("IS_PARENT", Val1 ).Replace("IS_CHILD", val2);

in my

str = "IS_PARENT, IS_CHILD_WITH_ROLE, IS_CHILD"; 

IS_CHILD is coming in two place so it is replacing both IS_CHILD.

I want to replace only exact word IS_CHILD.

how to do that?

Answer 1

You can use Regex.Replace

string newString = Regex.Replace(str, @"\bIS_CHILD\b", replacedText);

EDIT:
If you want to replace IS_PARENT with the same criteria as IS_CHILD (replacing the whole word only)

string  newString = Regex.Replace(newString, @"\bIS_PARENT\b", "NEW TEXT");
newString = Regex.Replace(str, @"\bIS_CHILD\b", replacedText);

OR (This is not optimized and in the answer because it is one way to replace a single word)

You can split the string based on the space, and then use string.Join to create a new string after replacing the complete word.

string str = "IS_PARENT, IS_CHILD_WITH_ROLE, IS_CHILD";
string replacedText = "SomeThing";
string newString = string.Join(" ", str.Split()
                                       .Select(r => r == "IS_CHILD" ? replacedText : r));

New String will be:

IS_PARENT, IS_CHILD_WITH_ROLE, SomeThing