I was reading and reviewing the following site and had a question.
https://www.geeksforgeeks.org/angle-bracket-in-java-with-examples/
In the explanations below they show class definitions followed by <T> and then when actually implementing these classes they use different types such as or as the parameters. My question is: is the '' notation actually a defined syntax in Java? In particular, is the T a necessary thing in order to define a "Generic"? And then does it basically mean that the parameters can be of multiple different types? Also, if anyone can reword or explain in simpler terms what the meaning of a generic is that would be very helpful. Thanks.
The <T> is indeed a syntax defined by Java, but you can use whatever name you want to name a type, you don't need to use T, for example this is valid:
public class Box<MyType> {
private MyType t;
public void set(MyType t) { this.t = t; }
public MyType get() { return t; }
}
But, stick with T or other common type names, as other people are already used to seeing those as the "generic types" so it makes reading your code simpler.
I recommend you read Java's Trail about Generics, where you can find the most commonly used type parameter names:
E - Element
K - Key
N - Number
T - Type
V - Value
S,U,V etc. - 2nd, 3rd, 4th types
As for "what the meaning of generics is", check this other page.