String Slicing in C#

Not only we can select a single character from a string, but we can also select a sequence of consecutive characters (e.g. substring) from a string.

To achieve this, we use the Substring() method like this:

string.Substring(startIndex, length);

This is called slicing a string. It returns the substring of length characters, starting at startIndex.

Here is an example:

string language = "JavaScript";
string substring = language.Substring(2, 6);

Console.WriteLine(substring); // Output: "vaScri"
Console.WriteLine(language); // Output: "JavaScript"

The startIndex is a zero-based index at which we start extraction and the length is the number of characters to extract.

The substring ends right before index startIndex + length. You can see in our example that the character at index 2 (v) was included, 6 characters were taken (indexes 2 to 7), and the character at index 8 (p) was excluded.

Also notice that language preserved its value. The slicing does not affect the original string. It just creates a brand new one representing the sliced substring.

If you omit the length, Substring() extracts to the end of the string:

string language = "JavaScript";
string substring = language.Substring(4);

Console.WriteLine(substring); // Output: "Script"