C# String - Insert() Method

---

---

The C# String Insert() method is used to return a new string in which a specified string is inserted at a given index position in this instance of string.

Exception

There are a few exceptions to this method −

• ArgumentNullException: When the value is null.
• ArgumentOutOfRangeException: When startIndex is negative or greater than the length of the string object.

Syntax

Following is the syntax of the C# string Insert() method −

 public string Insert(int startIndex, string value); 

Parameters

This method accepts the following parameters −

• startIndex: It represents the index position of current string where the new value will be inserted.
• value: It represents a string to be inserted at the specified position.

Return value

This method returns a new string. That is equal to the current string object. But the string is modified with a value inserted at the specified position.

Example 1: Insert Space Character

The following example inserts a space character in the fourth character position (i.e. the character at index 3) of a string using the Insert() method −

 using System; public class Program { public static void Main() { String original_str = "tutorialspoint"; Console.WriteLine("The original string: '{0}'", original_str); // modify the string... String modified_str = original_str.Insert(3, " "); Console.WriteLine("The modified string: '{0}'", modified_str); } } 

Output

Following is the output −

 The original string: 'tutorialspoint' The modified string: 'tut orialspoint' 

Example 2: Insert a String

Let us look at another example of the Insert() method. Here, we define a string, and between the string's words, we are inserting another one −

 using System; public class Program { public static void Main() { String str = "Hello World!"; String to_be_insert = "tutorialspoint"; Console.WriteLine("The original string: '{0}'", str); // modify the string... String modified_str = str.Insert(3, to_be_insert); Console.WriteLine("The modified string: '{0}'", modified_str); } } 

Output

Following is the output −

 The original string: 'Hello World!' The modified string: 'Heltutorialspointlo World!' 

Example 3: Insert at the Beginning of a String

In this example, we use the Insert() method to add a string at the beginning of the string, specifically at index position 0 −

 using System; class Program { static void Main() { string str = "World!"; string modified_str = str.Insert(0, "Hello "); Console.WriteLine(modified_str); } } 

Output

Following is the output −

 Hello World! 

Example 4: Insert at the End of a String

In this example, we use the Insert() method to insert a string at the end of the current string object −

 using System; class Program { static void Main() { string str = "Hello"; string to_be_insert = " tutorialspoint!"; // modified the string string modified_str = str.Insert(str.Length, to_be_insert); Console.WriteLine(modified_str); } } 

Output

Following is the output −

 Hello tutorialspoint!