To read a file we can use the Javascript FileReader object that gets the content of the file. File name, size & type can be found through the properties of the selected File object.

The concat() method can be used to merge two or more arrays. Duplicates in the merged array can be removed using a Set object.

A part of an array can be extracted with the Array.slice() method.

Javascript window.innerWidth and window.innerHeight properties gives the dimensions of the viewport window. window.outerWidth and window.outerHeight gives the dimensions of the full browser window that includes the location bar, menu etc.

The filter() method can be used to get intersection or difference of arrays. Duplicates can be eliminated by converting array to a Set object.

Union of arrays would represent a new array combining all elements of the input arrays, without repetition of elements.

BigInt is a new data type introduced in Javascript that can handle extremely large numbers. Such large numbers are typically created in financial sectors or in creating high-accuracy timestamps.

The Vibration API makes it possible for a web application to vibrate a mobile device with Javascript. Single or multiple vibrations can be performed with this.

The shift(), pop() and splice() methods can be used to delete elements from any position in the array.

The reverse() method can be used to reverse the order of elements in an array.

The push() / unshift() methods can add elements to end / front of an array. The splice() method can be used to add elements at any position in the array.

jQuery position() method gives the top-left position of the element relative to its offset parent element. Its equivalent in native Javascript can be found using the offsetTop and offsetLeft properties.

The Geolocation API makes it possible to retrieve the current geographical location of the user. Latitide, longitude, altitude and many other location information can be fetched.

jQuery offset() method gives the top-left position of the element relative to the whole document. In Javascript there is no native method that directly gives this value, we need to calculate it.

This tutorial shows how to create a slider / carousal from scratch using HTML, CSS & Javascript. Using a custom self-made slider can prevent inclusion of external plugins in your application.

Web development is entering to a totally new phase with WebAssembly coming in. With WebAssembly it is possible to run desktop like applications inside a browser.

A special thing about HTML data-attributes is that its values can be directly rendered through CSS also. Whenever value of data-attribute changes, new value can be rendered in the page automatically.

Custom data attributes (data-*) can be used to store extra information for an HTML element. In Javascript the dataset property of the element can be used to read and write its data attributes.

The Network Information API gives an idea of the underlying network. Getting the network type may help the application in giving a suitable experience to the end user.

In login forms, it is better to inform the user that his CapsLock is currently locked. State of the CapsLock key can be detected with the get​Modifier​State method in keyboard/mouse events.