Java Programming - MCQ Practice Questions

== compares object references (memory location), while .equals() compares the actual string content.

protected allows access within the same package and to subclasses even outside the package.

Constructors can be overloaded based on parameter count and types, but not on return type.

Following operator precedence: 5%2=1, 3*2=6, then 1+6-1=6

Static variables are shared among ALL instances of a class, not individual copies per object.

Private members are not inherited. They remain accessible only within the class they are declared in.

Static variables are initialized only once when the class is first loaded into memory, regardless of object creation.

Variables declared inside a method have local scope and are only accessible within that method. They are destroyed when the method returns.

This is valid method overloading. Two methods with same name but different parameters (method signature) is allowed in Java.

Evaluation: (true && false) || true = false || true = true. AND operator (&& has higher precedence than OR (||).

Java uses pass-by-value for all parameters. For objects, the value passed is the reference, but the reference itself is passed by value.

== compares object references (memory addresses). equals() method compares actual content/values and can be overridden.

s1 is created in string pool, s2 is a new object in heap. Though content is same, references are different, so == returns false.

Lambda expressions were introduced in Java 8, enabling functional programming. Syntax: (parameters) -> expression or statement

'this' is a reference variable that refers to the current object instance. It is used to distinguish instance variables from local variables with the same name, or to pass the current object as a parameter.

Method overloading allows multiple methods with the same name but different parameters (number, type, or order) in the same class. This is a way to implement compile-time (static) polymorphism.

Static methods belong to the class, not to any instance. They are called using the class name (e.g., ClassName.methodName()). They cannot directly access instance variables and cannot be overridden (though they can be hidden).

Accessing an array index that doesn't exist throws an ArrayIndexOutOfBoundsException at runtime. This is a checked exception that must be handled or declared.

When no access modifier is specified, it's called package-private or default access. Members with default access are accessible only within the same package, not from other packages.

'break' immediately exits the loop, while 'continue' skips the remaining statements in the current iteration and jumps to the next iteration.