When an element has been dragged in HTML to a valid drop target, the ondragenter attribute fires.ExampleYou can try to run the following code to implement the ondragenter attribute −                    #boxA, #boxB {             float:left;padding:10px;margin:10px; -moz-user-select:none; ... Read More

Use the tag to include groups of table columns.The HTML tag is used for specifying properties for a group of columns within a table. If you need to apply different properties to a column within a colgroup, you can use the HTML col tag within the colgroup tag.The ... Read More

Default constructors in Java:A constructor initializes an object when it is created. It has the same name as its class and is syntactically similar to a method. However, constructors have no explicit return type. There are two types of constructors namely −parameterized constructors − Constructors with arguments.no-arg constructors − Constructors ... Read More

HTML 5 audio tags can be styled. By using the audio tag with “controls” attribute, the default browsers player is used. You can customize by not using the browsers controls. By removing the controls attribute, you can hide the built in browser user’s interface −    Play    Pause    Vol+ ... Read More

Use the tag to add document title. The HTML tag is used for indicating the title of the HTML document. The body title is placed between the and the tags.ExampleYou can try to run the following code to learn how to add document title in HTML ... Read More

Annotations provide information about java elements. Annotations can be interpreted by compiler or IDE at compile time or by JVM at runtime. Annotations can be usedto show attributes of an element: e.g. @Deprecated, @Override, or @NotNullto describe the purpose of an element of the framework, e.g. @Entity, @TestCase, @WebServiceto describe ... Read More

Covariant return type refers to return type of an overriding method. It allows to narrow down return type of an overridden method without any need to cast the type or check the return type. Covariant return type works only for non-primitive return types.From Java 5 onwards, we can override a ... Read More

Following are the different types of keywords in java—Access modifiers − private, protected, public.Class, method, variable modifiers− abstract, class, extends, final, implements, interface, native, new, static, strictfp, synchronized, transient, volatile.Flow control− break, case, continue, default, do, else, for, if, instanceof, return, switch, while.Package control− import, package.Primitive types− boolean, byte, char, ... Read More

Before running Java programs on your machine you need to set two environment variables namely, PATH − The path environment variable is used to specify the set of directories which contains execution programs.When you try to execute a program from command line, the operating system searches for the specified program ... Read More

Yes, it is possible to use MySQL GROUP BY clause with multiple columns just as we can use MySQL DISTINCT clause. Consider the following example in which we have used DISTINCT clause in first query and GROUP BY clause in the second query, on ‘fname’ and ‘Lname’ columns of the ... Read More