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Articles on Trending Technologies
Technical articles with clear explanations and examples
How to pass an arrayList to another activity using intents in Android?
This example demonstrates how do I pass an arrayList to another activity using intends in android.Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.Step 2 − Add the following code to res/layout/activity_main.xml. Step 3 − Add the following code to src/MainActivity.javaimport android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.view.View; import android.widget.Button; import java.util.ArrayList; public class MainActivity extends AppCompatActivity{ Button button; ArrayList numbers = new ArrayList(); @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); ...
Read MoreHow to sell your Bitcoin?
Already own bitcoins but want either just exchange with some conventional currency or simply get rid of them considering them mere a bubble of widening hype. However, it is not as easy as buying them. Got lines of stress on your forehead? Do not worry! Here is the complete guide for your easy comprehension of the entire process −There are two ways to sell your bitcoins −ExchangesDirect TradeExchange Although, this carries a number of disadvantages yet exchanges appear to be one of the major solutions if you want cash out of the selling of your crypto. These exchanges play the role ...
Read MoreHow to print custom message instead of ErrorStackTrace in java?
An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed.Printing the Exception messageYou can print the exception message in Java using one of the following methods which are inherited from Throwable class.printStackTrace() − This method prints the backtrace to the standard error stream.getMessage() − This method returns the detail message string of the current throwable object.toString() − This message prints the short description of the current throwable object.Exampleimport java.util.Scanner; public class PrintingExceptionMessage { ...
Read MoreWhat is the difference between throw e and throw new Exception(e) in catch block in java?
An exception is an issue (run time error) occurred during the execution of a program. Here are some example scenarios −If you have an array of size 10 if a line in your code tries to access the 11th element in this array.If you are trying to divide a number with 0 which (results to infinity and JVM doesn’t understand how to valuate it).When exception occurs the program terminates abruptly at the line that caused exception, leaving the remaining part of the program unexecuted. To prevent this, you need to handle exceptions.There are two types of exceptions in java.Unchecked Exception ...
Read MoreHow IllegalArgumentException automatically handled inside 'if' condition in java?
Whenever you pass inappropriate arguments to a method or constructor, an IllegalArgumentException is thrown. It is a Runtime exception therefore there is no need to handle this at the time of compilation.ExampleThe valueOf() method of the java.sql.Date class accepts a String representing a date in JDBC escape format yyyy-[m]m-[d]d and converts it into a java.sql.Date object.import java.sql.Date; import java.util.Scanner; public class IllegalArgumentExample { public static void main(String args[]) { Scanner sc = new Scanner(System.in); System.out.println("Enter your date of birth in JDBC escape format (yyyy-mm-dd) "); String dateString = sc.next(); ...
Read MoreWhy can I throw null in Java and why does it upcast to a NullPointerException?
In Java there is default value for every type, when you don’t initialize the instance variables of a class Java compiler initializes them on your be-half with these values. Null is the default value of the object type, you can also manually assign null to objects in a method.Object obj = null;But, you cannot use an object with null value or (a null value instead of an object) if you do so, a NullPointerException will be thrown.Examplepublic class Demo { String name = "Krishna"; int age = 25; public static void main(String args[]) { ...
Read MoreWhen does a Java Array Throws a NullPointerException?
In Java there is default value for every type, when you don’t initialize the instance variables of a class Java compiler initializes them on your be-half with these values. Null is the default value of the object type, you can also manually assign null to objects in a method.Object obj = null;But, you cannot use an object with null value or (a null value instead of an object) if you do so, a NullPointerException will be thrown.Examplepublic class Demo { String name = "Krishna"; int age = 25; public static void main(String args[]) { ...
Read MoreWhat are try, catch, finally blocks in Java?
An exception is an issue (run time error) occurred during the execution of a program. For understanding purpose let us look at it in a different manner.Generally, when you compile a program, if it gets compiled without a .class file will be created, this is the executable file in Java, and every time you execute this .class file it is supposed to run successfully executing each line in the program without any issues. But, in some exceptional cases, while executing the program, JVM encounters some ambiguous scenarios where it doesn’t know what to do.Here are some example scenarios −If you ...
Read MoreWhat is the cause of NoSuchElementException and how can we fix it in java?
What is the cause of NoSuchElementException and how can we fix it in java?An exception is an issue (run time error) occurred during the execution of a program. When an exception occurred the program gets terminated abruptly and, the code past the line that generated the exception never gets executed. Each exception is represented by its respective class.Cause for NosuchElementExceptionThis is a Runtime exception i.e. it occurs at the execution time.While accessing the contents of a collection, array or other objects using the accessor methods of an Enumeration, Iterator or, tokenizer, such as next() or nextElement(), if you try to ...
Read MoreWhy variables defined in try cannot be used in catch or finally in java?
A class in Java will have three kinds of variables namely, static (class), instance and, local.Instance variables − These variables belong to the instances (objects) of a class. These are declared within a class but outside methods. These are initialized when the class is instantiated. They can be accessed from any method, constructor or blocks of that particular class.Class/static variables − class/static variables belong to a class, just like instance variables they are declared within a class, outside any method, but, with the static keyword.They are available to access at the compile time, you can access them before/without instantiating the ...
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