Generics In Java — Part 1 MCQs with Explanations

Generics in Java are tied to the type of objects, meaning they work at the instance level. Static methods belong to the class itself and are shared across all instances. Since generics are resolved at the object level, type parameters cannot be directly used within static methods. Why the other options are incorrect: Option A: Overloaded Methods Overloaded methods can have different generic type parameters. The compiler can differentiate them based on their method signatures, making generic type parameters valid for overloaded methods. Option B: Generic methods Generic methods explicitly use type parameters, and this is a common and valid usage of generics in Java. Option D: Overriding methods Methods with generic type parameters can be overridden. The overridden method must respect the same type parameter or use a wildcard (?).

To enable type-safe collections and eliminate type casting is the correct answer to “What is the main purpose of generics in Java”. This question is standard in competitive examination syllabi for Generics In Java.

`` is the correct answer to “Which symbol is used to denote a generic type parameter in Java”. This question is standard in competitive examination syllabi for Generics In Java.

An unknown type is the correct answer to “In a generic class, what does the wildcard ` ` represent”. This question is standard in competitive examination syllabi for Generics In Java.

It ensures type safety by allowing only specific types of elements is the correct answer to “What is the benefit of using generics with collections in Java”. This question is standard in competitive examination syllabi for Generics In Java.

Element type is the correct answer to “What does the `E` represent in generic class declarations in Java”. This question is standard in competitive examination syllabi for Generics In Java.

It restricts the generic type to be a subclass of `SomeClass` is the correct answer to “In Java generics, what is the purpose of the ` ` syntax”. This question is standard in competitive examination syllabi for Generics In Java.

The process of removing generic type information at compile time is the correct answer to “What is type erasure in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

`ArrayList` is the correct answer to “Which of the following is a generic class in Java”. This question is standard in competitive examination syllabi for Generics In Java.

It allows you to specify that the type must be a superclass of `T` is the correct answer to “What is the purpose of the `? super T` wildcard in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

It simplifies the instantiation of generic classes is the correct answer to “In Java generics, what is the purpose of the diamond operator (`<>`)”. This question is standard in competitive examination syllabi for Generics In Java.

`` is the correct answer to “Which keyword is used to define generic methods in Java”. This question is standard in competitive examination syllabi for Generics In Java.

It allows the method to accept arguments of any type is the correct answer to “What is the purpose of the ` ` wildcard in a method parameter in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

Compilation error is the correct answer to “What is the result of the following Java code? List list = new ArrayList<>(); list.add("Hello");”. This question is standard in competitive examination syllabi for Generics In Java.

`ClassCastException` is the correct answer to “In Java, which exception is thrown when there is a type mismatch due to generics”. This question is standard in competitive examination syllabi for Generics In Java.

It restricts the generic type to be a subclass or the same as the specified type is the correct answer to “What is the purpose of the `extends` keyword in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

A placeholder for a data type is the correct answer to “What does the term "type parameter" mean in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

It restricts the generic type to be a subclass or the same as `T` is the correct answer to “In Java generics, what is the purpose of the `? extends T` wildcard”. This question is standard in competitive examination syllabi for Generics In Java.

`ArrayList list = new ArrayList();` is the correct answer to “Which of the following is a valid use of generics in Java”. This question is standard in competitive examination syllabi for Generics In Java.

Compilation error is the correct answer to “What is the result of the following Java code? List list = new ArrayList<>(); list.add(new Integer(10));”. This question is standard in competitive examination syllabi for Generics In Java.

It allows you to specify that the type must be a superclass of `T` is the correct answer to “In Java generics, what is the purpose of the `? super T` wildcard”. This question is standard in competitive examination syllabi for Generics In Java.

Enhanced type safety and readability of code is the correct answer to “What is the primary advantage of using generics in Java”. This question is standard in competitive examination syllabi for Generics In Java.

None of These is the correct answer to “Which of the following is NOT a generic type parameter in Java”. This question is standard in competitive examination syllabi for Generics In Java.

To retrieve an element at the specified index is the correct answer to “What is the purpose of the `get(int index)` method in a generic list in Java”. This question is standard in competitive examination syllabi for Generics In Java.

To store a pair of values with different types is the correct answer to “In Java generics, what is the purpose of the `Pair ` class”. This question is standard in competitive examination syllabi for Generics In Java.

The removal of generic type information at compile time is the correct answer to “What does the term "type erasure" mean in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

`Map` is the correct answer to “In Java, which generic class is commonly used for creating key-value pairs”. This question is standard in competitive examination syllabi for Generics In Java.

Compilation error is the correct answer to “What is the result of the following Java code? List list = new ArrayList<>(); list.add(new Object());”. This question is standard in competitive examination syllabi for Generics In Java.

To represent an enumeration type is the correct answer to “In Java generics, what is the purpose of the `Enum ` interface”. This question is standard in competitive examination syllabi for Generics In Java.

A type parameter that has a specific upper or lower bound is the correct answer to “What does the term "bounded type parameter" mean in Java generics”. This question is standard in competitive examination syllabi for Generics In Java.

It creates a list of strings is the correct answer to “In Java, what is the result of the expression `List list = new ArrayList<>();`”. This question is standard in competitive examination syllabi for Generics In Java.

Generic type instance is the correct answer to “Which of these instance cannot be created”. This question is standard in competitive examination syllabi for Generics In Java.

7.0 is the correct answer to “What will be the output of the following Java program? import java.util.*; class Output { public static double sumOfList(List<? extends Number> list) { double s = 0.0; for (Number n : list) s += n.doubleValue(); return s; } public static void main(String args[]) { List<Double> ld = Arrays.asList(1.2, 2.3, 3.5); System.out.println(sumOfList(ld)); } }”. This question is standard in competitive examination syllabi for Generics In Java.

Array is the correct answer to “Which of these data type cannot be type parameterized”. This question is standard in competitive examination syllabi for Generics In Java.

Generic methods are methods that introduce their own type parameters is the correct answer to “What are generic methods”. This question is standard in competitive examination syllabi for Generics In Java.

36 is the correct answer to “What will be the output of the following Java program? import java.util.*; public class genericstack <E> { Stack <E> stk = new Stack <E>(); public void push(E obj) { stk.push(obj); } public E pop() { E obj = stk.pop(); return obj; } } class Output { public static void main(String args[]) { genericstack <Integer> gs = new genericstack<Integer>(); gs.push(36); System.out.println(gs.pop()); } }”. This question is standard in competitive examination syllabi for Generics In Java.

all of the mentioned is the correct answer to “Which of these Exception handlers cannot be type parameterized”. This question is standard in competitive examination syllabi for Generics In Java.

Hello 36 is the correct answer to “What will be the output of the following Java code? import java.util.*; public class genericstack <E> { Stack <E> stk = new Stack <E>(); public void push(E obj) { stk.push(obj); } public E pop() { E obj = stk.pop(); return obj; } } class Output { public static void main(String args[]) { genericstack <String> gs = new genericstack<String>(); gs.push("Hello"); System.out.print(gs.pop() + " "); genericstack <Integer> gs = new genericstack<Integer>(); gs.push(36); System.out.println(gs.pop()); } }”. This question is standard in competitive examination syllabi for Generics In Java.

extends is the correct answer to “Which of these keywords is used to upper bound a wildcard”. This question is standard in competitive examination syllabi for Generics In Java.

? is the correct answer to “Which of these is wildcard symbol”. This question is standard in competitive examination syllabi for Generics In Java.