To create a custom object in JavaScript, try the following codeExampleLive Demo                          var dept = new Object();          dept.employee = "Amit";          dept.department = "Technical";          dept.technology ="Java";          document.getElementById("test").innerHTML =          dept.employee + " is working on " + dept.technology + " technology.";          

Use the super() function to call the constructor of the parent class and access functions on an object's parent class.ExampleYou can try to run the following code to implement super()Live Demo                    class Department {             constructor() {}             static msg() {                return 'Hello';             }          }          class Employee extends Department {             constructor() {}             static displayMsg() {                return super.msg() + ' World!';             }          }          document.write(Employee.displayMsg());          

for…in loopThe “for...in” loop is used to loop through an object's properties.Here’s the syntax −Syntaxfor (variablename in object) { statement or block to execute }You can try to run the following example to implement ‘for-in’ loop. It prints the web browser’s Navigator objectExampleLive Demo var aProperty; document.write("Navigator Object Properties "); for (aProperty in navigator) { document.write(aProperty); document.write(""); } document.write ("Exiting from the loop!"); for…of loopThe “for…of” loop is used to loop through iterable objects, which includes Map, Array, arguments, etc.SyntaxHere’s the syntax −for (variablename of iterable){ statement or block to execute }ExampleHere’s an example showing ... Read More

The onsubmit event occurs when you try to submit a form. You can put your form validation against this event type. The following example shows how to use onsubmit. Here we are calling a validate() function before submitting a form data to the webserver. If validate() function returns true, the form will be submitted, otherwise it will not submit the data.     The HTML code snippet. …

The +function() {} notation is primarily used to force the parser to treat whatever follows the + as an expression. This is used for functions that are invoked immediately, for example,+function() { alert("Demo!"); }();However, + before a function is one of the symbol. You can add other options also like !, -, ~, also. Parentheses can also be used as shown below:(function() { alert("Demo!"); })();You can also use it like this:(function() { alert("Demo!"); }());

When a user visits your website, they do things like click on text and images and given links, hover over things etc. These are examples of what JavaScript calls events.We can write our event handlers in JavaScript or VBScript and you can specify these event handlers as a value of event tag attribute. The HTML5 specification defines various event attributes as listed below −AttributeValueDescriptionOfflinescriptTriggers when the document goes offlineOnabortscriptTriggers on an abort eventonafterprintscriptTriggers after the document is printedonbeforeonloadscriptTriggers before the document loadsonbeforeprintscriptTriggers before the document is printedOnblurscriptTriggers when the window loses focusOncanplayscriptTriggers when media can start play but might to ... Read More

To add a new line in JavaScript alert box, use the “”:alert("Line One Line Two");ExampleYou can try to run the following code add a new line in an alert box in JavaScript:Live Demo                                         Click the following button to see the result:                          

The onmouseout triggers when you move your mouse out from that element.ExampleYou can try to run the following example to learn how to call a JavaScript function from onmouseout eventLive Demo                                         Bring your mouse inside the division to see the result:                 This is inside the division          

The onmouseover event triggers when you bring your mouse over any element.ExampleYou can try to run the following example to learn how to call a JavaScript function from onmouseover eventLive Demo                                         Bring your mouse inside the division to see the result:                 This is inside the division          

The onsubmit event occurs when you try to submit a form. You can put your form validation against this event type. The following example shows how to use onsubmit. Here, we are calling a validate() function before submitting a form data to the webserver. If validate() function returns true, the form will be submitted, otherwise it will not submit the data.     The HTML    .......