Remove last occurrence of a string in a string

Question

I have a string that is of nature

• RTT(50)
• RTT(A)(50)
• RTT(A)(B)(C)(50)

What I want to is to remove the last () occurrence from the string. That is if the string is - RTT(50), then I want RTT only returned. If it is RTT(A)(50), I want RTT(A) returned etc.

How do I achieve this? I currently use a substring method that takes out any occurrence of the () regardless. I thought of using:

Regex.Matches(node.Text, "( )").Count

To count the number of occurrences so I did something like below.

 if(Regex.Matches(node.Text, "( )").Count > 1)
      //value = node.Text.Remove(Regex.//Substring(1, node.Text.IndexOf(" ("));
 else
     value = node.Text.Substring(0, node.Text.IndexOf(" ("));

The else part will do what I want. However, how to remove the last occurrence in the if part is where I am stuck.

Answer 1

The String.LastIndexOf method does what you need - returns the last index of a char or string.

If you're sure that every string will have at least one set of parentheses:

var result = node.Text.Substring(0, node.Text.LastIndexOf("("));

Otherwise, you could test the result of LastIndexOf:

var lastParenSet = node.Text.LastIndexOf("(");

var result =
    node.Text.Substring(0, lastParenSet > -1 ? lastParenSet : node.Text.Count());

Answer 2

This should do what you want :

your_string = your_string.Remove(your_string.LastIndexOf(string_to_remove));

It's that simple.