C# String Substring()

The Substring() method returns a substring from the given string.

Example

using System;
namespace CsharpString
{
    class Test
    {
        public static void Main(string[] args)
        {
            string text = "C# is fun";

// Returns substring of length 3 from index 6 Console.WriteLine(text.Substring(6, 3));
Console.ReadLine(); } } } // Output: fun

Substring() Syntax

The syntax of the string Substring() method is:

Substring(int startIndex, int length)

Here, Substring() is a method of class String.


Substring() Parameters

The Substring() method takes the following parameters:

  • startIndex - the beginning index of the substring
  • length - (optional) - length of the substring

Substring() Return Value

The Substring() method returns a substring from the given string.


Example 1: C# Substring() Without Length

using System;
namespace CsharpString
{
    class Test
    {
        public static void Main(string[] args)
        {
            string text = "Programiz";

// Returns substring from the second character string result = text.Substring(1);
Console.WriteLine(result); Console.ReadLine(); } } }

Output

rogramiz

Notice this line in the above example:

string result = text.Substring(1);

The code text.Substring(1) returns the substring from the second character of "Programiz".


Example 2: C# Substring() With Length

using System;
namespace CsharpString
{
    class Test
    {
        public static void Main(string[] args)
        {
            string text = "Programiz is for programmers";

// Returns substring of length 9 from the first character string result = text.Substring(0, 9);
Console.WriteLine(result); Console.ReadLine(); } } }

Output

Programiz

Notice this line in the above example:

string result = text.Substring(0, 9);

Here,

  • 0 (the first character of text) is the beginning index of the substring
  • 9 is the length of the substring

This gives us the substring "Programiz".


Example 3: C# Substring() Before Specific Character

using System;
namespace CsharpString
{
    class Test
    {
        public static void Main(string[] args)
        {
            string text = "C#. Programiz";

// Returns substring from index 0 to index before '.' string result = text.Substring(0, text.IndexOf('.'));
Console.WriteLine(result); Console.ReadLine(); } } }

Output

C#

Here, text.IndexOf('.') gives the length of the substring, which is the index of '.'.

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