Difference between equals() method and equality operator “==” in Java is asked quite frequently in beginner level Java interviews. Since both equals() and == operator are used for comparison so it is necessary to know the differences between these two in order to ensure correct usage of one of them.…
When you assign a value of one type to a variable of another data type, Java performs type conversion to accommodate the value to different type. This type conversion may happen automatically or you may need an explicit type casting to perform the type conversion. So, both of these terms…
Marker interface in Java is an interface with empty body. A marker interface does not contain constants or methods, examples of marker interface in Java are- java.util.RandomAccess java.rmi.Remote java.io.Serializable java.lang.Cloneable Marker interface adds special behavior Since marker interface is an empty interface so there are no methods to implement. It…
instanceof operator in Java is used to test the type of an object during run time. The syntax of instanceof operator in Java is as follows-
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1 |
objRef instanceof objType |
Here objRef is a reference to an instance. objType denotes a class type. Using instanceof operator you can check if objRef is of…
Access level modifiers in Java are used to set the visibility of the class, interface and the visibility of fields, methods and constructors of the class. Access level modifiers determine whether other classes can use a particular field or invoke a particular method of a given class. Types of access…
When you create an instance of a class, constructor is called to initialize the instance variables. An alternative to using a constructor to initialize instance variable is to use initializer block in Java. Initializer block is always executed when an instance of the class is created. General form of Initializer…
Once you create a class in Java that defines a new data type which can be used for creating object of that data type (class). Thus object in Java is an instance of the class, which gets its state and behavior from the class. Fields defined within a class are…
A class is the foundation for object oriented programming in Java language. Any logic that has to be implemented in Java must be encapsulated with in the class. Once a class is created in Java that defines a new data type which can be used for creating object of that…
Constructor overloading in Java is the process similar to method overloading which means with in a class you can have more than one constructor where the constructors differ in the number of parameters. What is the use of having overloaded constructor Constructor overloading in Java brings the flexibility of initializing…
Constructor chaining in Java is the process of calling one constructor from another constructor with in the same class or calling the parent class constructor from the child class. So constructor chaining in Java can be done in two ways- When calling one constructor from another with in the same…