How to define a variable in Unity using C#

In C#, all are categorized into the following types:

• Value types
• Reference types
• Pointer types

// basic values in Unity
int lives = 3;
float health = 100.0f;    // 100.0 will be treated as a double by default.
double heath = 100.0;
string playerName = "solider";


// reference type
GameObject go = new GameObject();


// pointers
Vector3* oldNew;
Vector3* curr;