When to use generic methods and when to use wild-card?

Question

I am reading about generic methods from OracleDocGenericMethod. I am pretty confused about the comparison when it says when to use wild-card and when to use generic methods.

Answer 1

Mainly -> Wildcards enforce generics at the parameter/argument level of a Non-Generic method. Note. It can also be performed in genericMethod by default, but here instead of ? we can use T itself.

package generics;

public class DemoWildCard {


    public static void main(String[] args) {
        DemoWildCard obj = new DemoWildCard();

        obj.display(new Person());
        obj.display(new Person());

    }

    void display(Person person) {
        //allows person of Integer,String or anything
        //This cannnot be done if we use T, because in that case we have to make this method itself generic
        System.out.println(person);
    }

}

class Person{

}

SO wildcard has its specific usecases like this.