Why do we need struct? (C#)

Question

To use a struct, we need to instantiate the struct and use it just like a class. Then why don\'t we just create a class in the first place?

Answer 1

This is a myth that struct are always created on heap. Ok it is right that struct is value type and class is reference type. But remember that

1. A Reference Type always goes on the Heap.
2. Value Types go where they were declared.

Now what that second line means is I will explain with below example

Consider the following method

  public void DoCalulation()
  {
        int num;
        num=2; 
  }

Here num is a local variable so it will be created on stack.

Now consider the below example

public class TestClass
{          
    public int num;
}
public void DoCalulation()
{
    TestClass myTestClass = new TestClass ();
    myTestClass.num=2;
}

This time num is the num is created on heap.Ya in some cases value types perform more than reference types as they don't require garbage collection.

Also remeber:

The value of a value type is always a value of that type. The value of a reference type is always a reference.

And you have to think over the issue that if you expect that there will lot be instantiation then that means more heap space yow will deal with ,and more is the work of garbage collector.For that case you can choose structs.