参数类型中的名称是否确定该类是否是通用的？

Question

I just started reading about generic classes. I'm wondering if the name of the parameter type affects what gets passed in. So does code 1 and 2 work exactly the same way? Are they both generic classes? Thanks!

// Code 1
public class Bar<AnyType> {
    private AnyType a;
}

// Code 2
public class Bar<Lalaland> {
    private Lalaland a;  
}

Answer 1

It works the exact same way, just as choosing a different variable name works the same way.

int anyInt = 5;

vs.

int lalaland = 5;

But always be careful that you choose a generic type parameter name different than an existing class name. While it's legal, it leads to plenty of confusion when the type parameter is mistaken for the class name.

// Don't do this.
public class Bar<Integer>  // confusing!

According to the Java tutorial on the subject ,

By convention, type parameter names are single, uppercase letters. This stands in sharp contrast to the variable naming conventions that you already know about, and with good reason: Without this convention, it would be difficult to tell the difference between a type variable and an ordinary class or interface name.

The most commonly used type parameter names are:

• E - Element (used extensively by the Java Collections Framework)
• K - Key
• N - Number
• T - Type
• V - Value
• S,U,V etc. - 2nd, 3rd, 4th types