CODEWITHSUNDEEP
javagenerics
Jericho
Jericho

Reputation: 10953

Generics with static methods

How this works without any Exceptoin ? Because T must be same in this case but one is String and another one is ArrayList<Integer>.

public static void main(String[] args) {
    Serializable s = pick("d", new ArrayList<Integer>());   
    System.out.println("s:"+s);
}
static <T> T pick(T a1, T a2) {
    return a2;
}

Upvotes: 2

Views: 82

Answers (2)

Dici
Dici

Reputation: 25980

Since you return an object of type T and you store it into a variable of type Serializable, I guess that the compiler infers that T is Serializable in your call, so both String and ArrayList are eligible to be parameters of pick.

Upvotes: 1

rgettman
rgettman

Reputation: 178343

The compiler uses type inference to determine the type of T. It picks the most specific type that works for all types considered. Here, the type of s is Serializable, and you pass in a String and an ArrayList<Integer>. Both String and ArrayList are Serializable, with no other relation, so the inferred type for T is Serializable.

Upvotes: 7

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