What are unary + and - operators?

Operators that work on only one operand are called unary operators. The unary + operator is used to emphasize the sign of the operand, whereas the unary - operator is used to arithmetically negate the value of the operand. Both of these operators appear before the operand. For example, +x -x......[read more]

What is the for loop?

The for loop is the most versatile looping construct. It is used to continuously execute a block of code until a particular condition is satisfied. It comprises three parts: initialization, condition, and iteration. The initialization portion is generally an expression that sets the value of......[read more]

What are reference variables?

Variables holding the reference to an object are called reference variables. The initial value of a reference variable depends on its place of declaration. Class variables and instance variables are initialized with a special null value, whereas variables declared inside code blocks are not......[read more]

What is the bitwise OR operator?

The bitwise OR operator is a binary operator that produces a 1 bit if either of the bits in the operands is a 1. It is denoted by the symbol |. It can be applied to the integer type operands, i.e., byte, short, char, int, and long. The table given below shows the outcome of the OR operation when......[read more]

What are integer literals?

Numeric values having no decimal parts are called integer literals. These values can be expressed in decimal, octal, and hexadecimal forms. By default, integer literals are in decimal form. The decimal form contains a sequence of decimal digits (0 to 9), the octal form contains a sequence of......[read more]

What is the bitwise XOR operator?

The bitwise XOR operator is a binary operator that produces a 1 bit if exactly one of its operands is 1. Otherwise, it produces a 0 bit. It is denoted by the symbol ^. It can be applied to the integer type operands, i.e., byte, short, char, int, and long. The table given below shows the outcome......[read more]

What is an abstract class?

An abstract class is a class that is partially implemented. It provides design convenience. An abstract class consists of one or more abstract methods that are declared but left unimplemented. It is the responsibility of subclasses that extend an abstract class to implement the unimplemented part......[read more]

What is the equals() method?

The equals() method checks if some other object passed to it as an argument is equal to the object on which this method is invoked. The default implementation of the equals() method is in the Object class, the mother of all classes in Java. The equals() method in the Object class checks if two......[read more]

What is the Double class?

The Double class is a type of wrapper class that wraps a primitive type double value in an object. As the Double class is a subclass of the abstract class Number, it implements the doubleValue(), floatValue(), longValue(), and intValue() methods, which are declared as abstract in the Number......[read more]

What is the instanceof operator?

The instanceof operator is a binary operator that determines at runtime whether its left operand is an instance of its right operand. Syntax: obj instanceof type where, obj (the left operand) must be an instance of a class and type (the right operand) may be a class, interface, or......[read more]