I am trying to replace a specific sub string from a string in C#.
My string is: This is a car.
And I am trying to replace 'a' with string.Empty from the string with this code:
data = data.Replace("a", string.Empty);
But my output is :
This is c r.
I just want to remove isolated occurence of 'a', and not when this char/word is used in some other word (like car).
I want a output like ths: This is car.
How can I do this in C#?
You need a regex pattern that only matches "a" on word boundaries. "\b" in a regex pattern denotes a word boundary:
Regex.Replace("this is a car", @"\ba\b", "")
If you want to match uppercase "A" as well, make sure your pattern is ignoring case (RegexOptions.IgnoreCase) or explicitly add "A" to the pattern like "\b[Aa]\b".
What do you mean with 'isolated occurence'? Is it perhaps something like this you're really after:
data.Replace(" a ", " ");
You need to do couple of different cases but it is certainly possible:
a in the beginning of the sentence "A car went by" -> s.StartsWith("A ")
a in the middle "this is a car" -> Replace(" a ", " ")
search for the spaces too.
data = data.(" a ", " ")
You can use a regex and limit to instances of 'a' that qualify as a word.
string input = "This is a car. A thing to watch out for.";
string output = Regex.Replace(input, "\ba\b", "");
//Results in "This is car. A thing to watch out for."
You can also add a character class to deal with capital and lower case, as well as any other characters. ex. \s[Aa]\s
The \s means any white space character
Search for the string " a " instead, and replace with a space to keep the sentence construct correct;
data = data.Replace(" a ", " ");
StringBuilder.Replace Method
Replaces all occurrences of a specified character or string in this instance with another specified character or string.
OVERLOADS Replace(Char, Char) Replaces all occurrences of a specified character in this instance with another specified character.
Replace(String, String) Replaces all occurrences of a specified string in this instance with another specified string.
Replace(Char, Char, Int32, Int32) Replaces, within a substring of this instance, all occurrences of a specified character with another specified character.
Replace(String, String, Int32, Int32) Replaces, within a substring of this instance, all occurrences of a specified string with another specified string.
string myString = "This is a car.";
StringBuilder sb = new StringBuilder(myString);
sb.Replace(' a ', ' ');