Core java

In this article, we are going to see how we can convert from a String data type into integer data type in Java. Conversion Modes There are two ways in which String data can be converted into integer. They are: Using the static method parseInt(String) of the java.lang.Integer wrapper class Using the static method valueOf(String) […]

In this posts, we will see how to create a list of lists in java. You can easily create a list of lists using below syntax List<ArrayList<String>> listOfLists = new ArrayList<ArrayList<String>>(); or ArrayList<ArrayList<String>> listOfLists = new ArrayList<ArrayList<String>>(); One of the Usecase This is generally useful when you are trying to read a CSV file and […]

In this post, we will see about "Can we overload main method in java".This is one of the most asked Core java interview questions. Yes, we can overload main method in java but when you run your program, JVM will search for public static void main(String[] args) and execute that method. Overload main method in […]

In this post, we will about Dynamic method dispatch which is also referred as run time polymorphism. Dynamic Method Dispatch Dynamic method dispatch is a technique by which call to a overridden method is resolved at runtime, rather than compile time.When an overridden method is called by a reference, then which version of overridden method […]

No, we can not override static method in java. Static methods are those which can be called without creating object of class,they are class level methods. On other hand,If subclass is having same method signature as base class then it is known as method overriding. Its execution decided at run time. Below are the reasons why […]

In this post, we will see an error(Could not reserve enough space for 2097152kb object heap object heap) which you might have encountered while dealing with JVM.We will see how can we fix this issue. error occurred during initialization of vm could not reserve enough space for 2097152kb object heap is generally raised when Java […]

In this post, we will about an error: Could not create the Java virtual machine in java. You can provide VM arguments to provide heap size for Java virtual machine. You can specify VM argument -Xms and -Xmx in form of KB, MB or GB. For example: Let’s say you want to specify maximum heap […]

In this post, we will see how to fix "class interface or enum expected" error in java. There can be multiple reason for getting this error. Due to method outside class body This error you will generally get when you have accidentally put your method outside class body. Let’s see with the help of simple […]

In this post, we will see how to fix "illegal start of expression" in java. You will get this error while using javac command in command prompt. In eclipse or any other ide, it will give you more helpful compile time error. There can be multiple reasons for getting this error. Using private, public or […]