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Java: In Java, which comparison about Generics and Wildcards is accurate?

Difficulty:

Easy

Questions:

1

Time Limit:

2 minutes

Passing Score:

100%

Question

In Java, which comparison about Generics and Wildcards is accurate?

  1. There is no practical difference in behavior, performance, or API design when Generics and Wildcards is involved.
  2. The oldest option related to Generics and Wildcards is always the right production choice regardless of context.
  3. ? extends is for producing values safely, while ? super is for consuming values into a structure.
  4. Differences around Generics and Wildcards are mostly cosmetic, so correctness and maintainability do not change.

Hint

Focus on the behavior or tradeoff, not just the keyword.

Answer and rationale

Correct answer: C. ? extends is for producing values safely, while ? super is for consuming values into a structure.

? extends is for producing values safely, while ? super is for consuming values into a structure. This is the comparison that usually separates memorization from understanding.

Track: Java