Actually, MySQL event scheduler is a process that runs in the background and constantly looks for the events to execute. But before we create or schedule an event we just have to start the scheduler. It can start with the help of the following statement −mysql> SET GLOBAL event_scheduler = ... Read More

Following example compares two strings by using str compareTo (string), str compareToIgnoreCase(String) and str compareTo(object string) of string class and returns the ascii difference of first odd characters of compared strings.Example Live Demopublic class StringCompareEmp{    public static void main(String args[]) {       String str = "Hello World";   ... Read More

Single Row Sub QueryA single-row subquery is used when the outer query's results are based on a single, unknown value. Although this query type is formally called "single-row, " the name implies that the query returns multiple columns-but only one row of results. However, a single-row subquery can return only ... Read More

In MySQL, basically the precedence of ! operator in comparison with NOT operator depends upon the enabling or disabling of HIGH_NOT_PRECEDENCE SQL mode as follows −Disabled HIGH_NOT_PRECEDENCE SQL − In this case, ! the operator has higher precedence than NOT operator.Enabled HIGH_NOT_PRECEDENCE SQL − In this case, ! the operator has ... Read More

We can generate random numbers using three ways in Java.Using java.util.Random class − Object of Random class can be used to generate random numbers using nextInt(), nextDouble() etc. methods.Using java.lang.Math class − Math.random() methods returns a random double whenever invoked.Using java.util.concurrent.ThreadLocalRandom class − ThreadLocalRandom.current().nextInt() method and similar othjer methods return ... Read More

A method catches an exception using a combination of the try and catch keywords. A try/catch block is placed around the code that might generate an exception. Code within a try/catch block is referred to as protected code, and the syntax for using try/catch looks like the following −Syntaxtry { ... Read More

Local VariableLocal variables are declared in methods, constructors, or blocks.Local variables are created when the method, constructor or block is entered and the variable will be destroyed once it exits the method, constructor, or block.Access modifiers cannot be used for local variables.Local variables are visible only within the declared method, ... Read More

Final Static VariablesClass variables also known as static variables are declared with the static keyword in a class, but outside a method, constructor or a block.There would only be one copy of each class variable per class, regardless of how many objects are created from it.Static variables are normally declared ... Read More

java.io.File class provides following useful methods to figure out the free disk space available.Sr.No.Method & Description1public long getFreeSpace()Returns the number of unallocated bytes in the partition named by this abstract path name.2public long getTotalSpace()Returns the size of the partition named by this abstract pathname.3public long getUsableSpace()Returns the number of bytes ... Read More

With Java 9, new factory methods are added to List interface to create immutable instances. These factory methods are convenience factory methods to create a collection in less verbose and in concise way.Old way to create collectionsExampleimport java.util.ArrayList; import java.util.Collections; import java.util.List; public class Tester {    public static ... Read More