How to solve error CS1520?

Question

C++ / C#

The code:

private OnCollisionEnter2D(Collision2D collision)
{
  if (collision.gameObject.tag == "Ground")
    isGrounded = true;
}

private OnCollisionExit2D(Collision2D collision)
{
  if (collision.gameObject.tag == "Ground")
    isGrounded = false;
}

Answer 1

void should have been added

private void OnCollisionEnter2D(Collision2D collision)
{
if (collision.gameObject.tag == "Ground")
isGrounded = true;
}

private void OnCollisionExit2D(Collision2D collision)
{
if (collision.gameObject.tag == "Ground")
isGrounded = false;
}

Answer 2

you only return the value if the condition is met, add else or return by default.
and read the documentation there everything is written
https://docs.microsoft.com/ru-ru/dotnet/csharp/mis...