How to capture out of memory exception in C#?

The System.OutOfMemoryException occurs when the CLR fail in allocating enough memory that is needed.

System.OutOfMemoryException is inherited from the System.SystemException class.

Set the strings −

string StudentName = "Tom";
string StudentSubject = "Maths";

Now you need to initialize with allocated Capacity that is the length of initial value −

StringBuilder sBuilder = new StringBuilder(StudentName.Length, StudentName.Length);

Now, if you will try to insert additional value, the exception occurs.

sBuilder.Insert(value: StudentSubject, index: StudentName.Length - 1, count: 1);

The following exception occurs −

System.OutOfMemoryException: Out of memory

To capture the error, try the following code −

Example

 Live Demo

using System;
using System.Text;

namespace Demo {
   class Program {
      static void Main(string[] args) {
         try {
            string StudentName = "Tom";
            string StudentSubject = "Maths";
            StringBuilder sBuilder = new StringBuilder(StudentName.Length, StudentName.Length);
            // Append initial value
            sBuilder.Append(StudentName);
            sBuilder.Insert(value: StudentSubject, index: StudentName.Length - 1, count: 1);
         } catch (System.OutOfMemoryException e) {
               Console.WriteLine("Error:");
               Console.WriteLine(e);
         }
      }
   }
}

The above handles OutOfMemoryException and generates the following error −

Output

Error:
System.OutOfMemoryException: Out of memory