Yes, use new RegExp(pattern, flags) to achieve this in JavaScript.You can try to run the following code to implement JavaScript regex using string variables −                    var str = 'HelloWorld'.replace( new RegExp('hello', 'i'), '' );          document.write(str);          

To get only the else part, just negate, using ! the operator in JavaScript. You can try to run the following code to achieve this −var arr = {}; if (!(id in arr)) { } else { }In addition, if you want the existence of a property in an object, then use hasOwnProperty −if (!arr.hasOwnProperty(id)) { } else { }

To create a syntax-highlighting code with JavaScript, use the prettify library. Add the following in your code to add the library for syntax highlighting −To use it, add the following to your tag −    Code comes here

Use the keydown event in JavaScript to get to know which keys are pressed at once. The following is the script −Examplevar log = $('#log')[0],    keyPressed = []; $(document.body).keydown(function (evt) {    var li = keyPressed [evt.keyCode];    if (!li) {       li = log.appendChild(document.createElement('li'));       keyPressed [evt.keyCode] = li;    }    $(li).text(Key Down: ' + evt.keyCode);    $(li).removeClass('key-up'); }); $(document.body).keyup(function (evt) {    var li = keyPressed [evt.keyCode];    if (!li) {       li = log.appendChild(document.createElement('li'));    }    $(li).text('Key Up: ' + evt.keyCode);    $(li).addClass('key-up'); });

JavaScript uses a semi-colon (;) to avoid any confusion in code, especially the beginning of a new line.ExampleYou can still use the following to avoid any chaos in the code −return {    'var':myVal } // using semi-colon; (function( $ ) {    // }

In this tutorial, we will learn how and why ‘z’[‘toUpperCase’]() works in JavaScript. From the given format, we can say that it calls the toUpperCase() method for the ‘z’ string. It will work the same as the toUpperCase() method, which we invoke by taking any string as a reference. Let’s understand the syntax of the ‘z’[‘toUpperCase’]() below. Syntax let result = 'z'['toUpperCase'](); // returns 'Z', string in upper case The above syntax is same as the below. Example let string = 'z'; let result = string.toUpperCase(); Why does ‘z’[‘toUpperCase’]() work? In JavaScript toUpperCase() method is used to convert ... Read More

To display million of rows of data to the users in a grid, use any of the following grids −S. NoGridDescription1DataTablesAllows adding advanced interaction controls to any HTML table.2IngridAllows resizing columns, paging, sorting, row and column styling to tables.3SlickGridUses virtual rendering to allow you to work with hundreds of thousands of items.Let us see the features of SlickGrid −Easily customizableComplete keyboard navigationEasily handles hundreds of thousands of rowsQuick rendering speedColumn autosizing availablePluggable cell formatters availableAllos creating new rows

The JavaScript equivalent to PHP explode() is split(). To get the data after the first colon, try to run the following code.Example                    var str = '087000764008:Rank:info:result';          var arr = str.split(":");          document.write(arr[1] + ":" + arr[2]);          

In this tutorial, we will learn how to hide HTML element with JavaScript. Hiding an HTML element can be performed in different ways in JavaScript. In this tutorial, we will see the three most popular ways of doing it − Using the hidden property Using the style.display property Using the style.visibility property Generally, we use the hidden attribute to hide a particular element. We can toggle between hiding and showing the element by setting the hidden attribute value to true or false, respectively. In the other two ways, we use the style object of the element. We ... Read More

In this tutorial, we will learn how to display an HTML element using JavaScript. HTML elements are the components that make up an HTML format file. These components are in charge of constructing web pages and defining their content. In HTML, an element typically consists of a start tag (tag name), a closing tag (tag name), and any text that is added in between. A collection of end tags, start tags, content, and attributes is what constitutes an element technically. Some HTML elements are − Starting Tag Content Ending Tag This is a paragraph. ... Read More