To convert String to double in Java you can use one of the following options- Double.parseDouble(String s)– Returns a new double initialized to the value represented by the specified String. Throws NumberFormatException if the string does not contain a parsable double. Double.valueOf(String s)– Returns a Double object holding the double…
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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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…
DelayQueue in Java is an implementation of BlockingQueue interface and is part of java.util.concurrent package. DelayQueue in Java is an unbounded queue that’s where it differ from ArrayBlockingQueue which is a bounded queue. Delayed interface DelayQueue can store elements only of type Delayed. There is an interface Delayed in Java…
SynchronousQueue in Java is an implementation of BlockingQueue interface and is part of java.util.concurrent package. SynchronousQueue in Java is different from other BlockingQueue implementations like ArrayBlockingQueue and PriorityBlockingQueue because a synchronous queue does not have any internal capacity, not even a capacity of one. So, each insert operation in SynchronousQueue…
PriorityBlockingQueue in Java is an implementation of BlockingQueue interface and is part of java.util.concurrent package. PriorityBlockingQueue is an unbounded queue PriorityBlockingQueue is logically unbounded that’s how is differ from ArrayBlockingQueue which is a bounded queue and LinkedBlockingQueue which is optionally-bounded. PriorityBlockingQueue though unbounded is created with an initial capacity which…
LinkedBlockingQueue in Java is an implementation of BlockingQueue interface and is part of java.util.concurrent package. LinkedBlockingQueue has the features of both ArrayBlockingQueue and DelayQueue. ArrayBlockingQueue is a bounded blocking queue where as DelayQueue is an unbounded blocking queue. LinkedBlockingQueue sits in the middle as it is an optionally-bounded blocking queue…
ArrayBlockingQueue in Java is an implementation of BlockingQueue interface and is part of java.util.concurrent package. ArrayBlockingQueue is a bounded blocking queue which internally uses an array to store elements. This queue orders elements FIFO (first-in-first-out). The head of the queue is the element that has been on the queue the…